(Thanks, MyJourney, for your earlier compliment.)
Thanks, Captain, for your summary. I think you're probably spot on.
Pfree, the description of your father is a perfect description of my Sag, as well. I didn't want to reveal too much of his personal details, but now I see how helpful that might be...
He told me when we met that he knew the day of his wedding that he probably shouldn't ever get married. He went ahead with the marriage (the "fun" was already paid for) and ended up having the same kind of relationship as your folks did. He has a great command of language and has the ability to quite rapidly shred anyone in an argument, and he admits that he did so frequently with his spouse. I think this stems from his learning at a young age to protect/defend himself from possible hurt. He said most of his (24?) years of marriage were comprised of arguments and finding avenues of escape, mostly in work, where he was able to create scenarios that handily kept him away from home. His children took his absences personally. And while he was miserable for years, he hung on, I believe out of guilt for not being able to "do" it right. He would probably still be unhappily married today had it not been for his spouse serving him with divorce papers.
He is a lover of animals and the first one to cry about something touching or sad. He has become reclusive, and although he can easily blame that on economic hard times, I believe he prefers it to cohabiting so he can avoid the associated responsibilities. And yet he seems to long for true intimacy...
(Hey SHINY, is your name from the Firefly series? I LOVED that show, and the Serenity movie!!)
Captain, this thread has been all over the map, and I'm not sure I can actually answer your original question (why), but I can offer another scenario that further confirms your observations.
I met and started dating a Sag shortly after my divorce became final in 2006. Having come from a marriage to a Virgo (very suppressive individual, ultimately not a good match for my natural Gemini tendencies), I was drawn to this man's "just want everything/everyone to be joyous" attitude, which was such a release after a good part of 22 years of spiritual confinement. I was also taken by his boyish curiosity, his constant quest for knowledge of all things, and his ability to idealize most everything. The consummate optimist, it was mostly a happy and heady experience being with him. But the ideals he so charismatically described to me (the details of how our lives COULD be together) did not and probably never will come to pass, as these seem to exist only in his "perfect world" mind. And what's that you say about making plans? If my schedule didn't work with his, he would go ahead and do his thing, regardless of my feelings, never thinking past the fun of the moment and his own happiness/fulfillment/joy. These natural tendencies are perceived by me and most other folks as SELFISH, although the Sag's mind, when forced to consider the matter, never seems to arrive at that conclusion. And when he presents his side of the argument, the thought process actually begins to sound logical - in his favor! Maddening! What I have come to see consistently, though, is that his on-going search for joy for joy's sake means forsaking day-to-day responsibilities in the hopes of achieving the ultimate high - play now, explain/apologize later. Often this equates to rarely setting goals, which could relate to what a lot of Sag's are saying about their fear of being hurt or hurt again, personally or professionally - if you don't set the goal, you can't fail in your efforts to achieve the goal; no failure, no disappointment/sadness/hurt.
But why do Sag's so often get hurt? As with most Sag's I've known, mine has a truly sweet and innocent nature, and all who know him say that he is the dearest of men - loyal to the core - and that they would do anything for him because he would give them the shirt off his back. These same people, though, truly wish that he WOULDN'T give them the shirt of his back, because they know that sometimes it's foolish to do so. They see him as TOO trusting and TOO giving, to the point that others take advantage of him, over and over. They watch him remain doggedly loyal to people who hang on to him for his "fun" factor in the good times, and then they see how deeply wounded he becomes when he realizes these same people aren't willing to stand by him in the difficult times. And after much consoling and offering what they believe to be the wise counsel he needs to finally get better at life, they watch again (with hands thrown in the air and heads shaking in utter disbelief) as their sweet Sag reaches out to the very same hangers-on, with genuine sincerity, to be sure that THEY will be okay! Ultimately, his friends and I see him as a child for whom we care deeply but who never seems to want to grow up and learn life's lessons - a true Peter Pan in every sense. And as much as Never-Never Land is a wonderful place to visit, most of us know that we must, at some point, go home and get a real life. It's sad and sobering, but it's reality.
I don't know why Sag's do what they do, but I hope your quest produces some answers because I love my Sag men. I had boyfriends through high school and college who were Sag's and my current business partner is a Sag (a day-to-day mix of creative bliss and frustration for his inconsistent dependability - not sure how long it will last). For all the frustrations they carry with them, I seem to be hopelessly drawn to them, and maybe that's because some of MY life's lessons are to be learned through my experiences with them. But I have a son who is a Sag (a musician - yikes!) and I so dearly want him to have a fruitful and fulfilling life, free from the painful episodes most of the Sag's I know (and have known) have been through. The good thing is my son knows about his natural tendencies, understands that some may not be to his benefit, and is open to learning as much as he can to avoid what so often become Sagittarius land mines.
As much as we who love them know that we can never change a Sag (and a Sag would HATE us for trying to!), it would be great to learn to more effectively speak their language (communication is the key to understanding!). A mind bending topic, to be sure, Captain, but I look forward to your future enlightenment!