just because your own game isn't fun for the dev to play doesn't mean they don't have fun making games. they have fun *making* games, not playing them
@c.a. sinclair - yeah, i wasn't disagreeing with you, just with geti -- he seems to imply that if a game isn't fun for the developer, that means they don't enjoy making that game. but that isn't the case, you can enjoy making a game even when playing that game isn't fun
Clearly the enjoyment someone derives from any activity is contingent on far too many factors to make absolute claims, but for me it'd take a lot of the enjoyment out of development.
I don't play many other games these days because I'm too busy making them as well, but playtesting has always been a crucial part of development for me - If I wasn't having fun jumping around/exploring/collecting/shooting/whatever I'd try and find what was making me not have fun and rip that bit out. If the thinking involved in finding the crap bit lead me to the conclusion that the sheer premise my game wasn't enjoyable, I'd stop working on the game.
Knowing how a system works has never put me off enjoying what that system does. There was a point in my life where I could take apart a bike and put it together again, and that didn't stop me riding it.
There's nothing to explore when you created all of the maps, designed the placement, and placed all the vegetation meticulously by hand.
Sounds like elf talk to me

Moreso than elf talk though, it's bringing me to realise that perhaps if you spend several times longer to make the game than your more-dedicated-than-average player would spend to play it, you're likely end up not really enjoying the end product.
Most of the heavily content driven games that I've started working on, I've given up on for precisely that reason - I stopped having fun with it.
It's late and I doubt I'm explaining myself very well, but I'm fairly sure there's a lost garden article on that last point somewhere...
http://www.lostgarden.com/2010/12/steambirds-survival-goodbye-handcrafted.html basically you get more fun from less work by not meticulously placing that piece of grass there and that piece of grass there.
This is getting wildly offtopic and rant-y so I'll stop typing now, I'd like to have a discussion about this in real time at some point (IRC?). It just seems that it's backwards to get to the end of building something that's meant to be entertaining and engaging and say "bleh, not playing that again!"