Giving up on a game line

For the second time in my gaming life now I've reached a point when I realise I'll probably never play or run a particular game line ever again - so I want to get rid of my books.

Does this happen to others?

The first time was with Rolemaster. I was introduced to it in uni, and soon converted my long-running AD&D game to it, and enjoyed it. I went off into the army and played other games, but after that returned to it for another long campaign. 

Then one day I sat down and played with K as a GM. It was awful. It was ages looking up charts, by the time we found out if we our characters lived or died we no longer cared. My character couldn't do anything, the randomness of the dice rolls was so much higher than any skill for anyone under 10th level that it was easier not to worry and just roll the dice. Half the time when I sprinted I ended up moving at slower than walking pace. 

After the session I said to another player, T - "Mate, it's not that bad when I GM, is it?"
"No," he said.
"Then why was it so fucking awful this time? This doesn't feel like the same system."
"It's different because you ignore the rules. You roll the dice and pretend to look up some chart and use that time to just make up what happens next."
"But -" I said, not wanting to admit that he'd pegged me perfectly."
"Look, you didn't realise the rules were shit because you never used them."
"Oh, alright then."

After that I realised I could never GM or play Rolemaster again. Why have this big pile of rules you never use? Get some other system where you do use the rules. I went to throw the books away, but T being a true gamer said, "no! I'll add them to my collection." So away went Character Law, Arms & Claw Law, Spell Law, Companion, Companion II through to Companion VII, and so on. Hundreds of dollars of books, gone.

Now something similar's happened with GURPS. In this case, I do enjoy the system in itself, it's just that nine-tenths of the gamers I meet never read the rules, so when GMing I have to just handwave over the details or we'll never get anything done. 

If you have a detailed system and the details come up regularly and people enjoy them, that's great - but if you have to handwave them all, why have them? That's what I thought when I got GURPS Martial Arts - my players can't even remember the difference between All-Out Attack (double) and All-Out Attack (strong), so what'd be the point in having Committed Attack or Defensive Attack? Again, why have this big pile of rules you never use? 

I just don't see any prospect of a group where even half the players really care about all that detail. Playing GURPS and ignoring the detail is like playing Ars Magica and nobody being wizards. You could do it, but what for?

I wrote to my two GURPS GM mates asking if they wanted to buy the books.

"How much?" said one.
"I dunno," I said, "I haven't sold any games since about 1985, I normally just lose them or give them away. Normal secondhand price is half new price, yeah? New they were $60 or so - nowadays in Mind Games they're as much as $80. So probably $30 each?"
"Wow thats nearly $300...did you really spend $600 on all those books?"
"Shit, I s'pose I did. But it wasn't all in one go! Bah, you have a bigger stack than me, you must have spent thousands!"

Rolemaster I gave up because I didn't want to run or play it anymore, GURPS I'm giving up because though I like it and others will play it, we'd be ignoring nine-tenths of it and so lugging around all those books to sessions is pointless.

So to me this is a big deal, having spent all that money on the books, all that time reading them and running or playing games with them. But now giving them up... 

I'm sure I can't be the only one who reaches a point where they realise they should just give away or sell a whole line of game books because they're never going to play them again. What about you guys?