Although I have played and enjoyed some of the crunchier games out there, sometimes they just start to feel more exhausting than fun. I've also found it hard to get players to buy into games where you have 20+ different questions/choices during character creation.
Ontop of those, sometimes a systems release schedule has made me stop wanting to run the game, I am personally not a huge fan of games that put out 3+ books a year,
This will vary from person to person very much and it stems from what are they looking for in a game. Some love the crunch (comparing values and looking up tables) or rules-heavy systems (having rules defined for everything they could do in a game) and expect the system to be build in a way that system mastery is required. Some don't and will never read the CRB and I don't think it should be frowned upon.
My players liked the level of customization Shadowrun offers, with all the grip modifications and types of bullets. But then the only ones that didn't keep asking "how my main thing works, again?" were the ones who focused on ranged combat.
I probably could be a player in SR or D&D but I've discovered that for being GM, Savage Worlds (two dice defined by your character sheet to throw, against TN 4 in most cases) is the most crunch I can work with.
And max two books with rules; lore books - the more the merrier.
The only ones that didn't keep asking "how my main thing works, again?"
This issue is probably the most draining for me. When I ran Shadowrun I warned my players that it was crunchy, and they promised me that they would learn how to play their classes. The streetsam did –the decker, rigger, adept, and technomancer did not.
Yeah. And once they've tricked out their ponies, they go on a run and the decker asks "what programs does the enemy spider run?" or "what chrome do they have?". And the real answer is "I don't know, they roll 16 for their main and 12 for everything else because they are low/mid-tier corp security".
Or I would have to sit and build a bunch of mooks. And even if I had a roster of these (there are some nice generators for mooks with all the similar gear choices etc), then a simple shootout on a street transforms into math-fest and keeping track of which hand that mook uses for this attack.
Which for me moves the game from "you are taking part in the dispute between this corp and that one" into something more like a wargame. And that is too much for me