Depends. I've seen people take it too far. I don't think children learn to respect anyone or anything through having every last whim catered to. That said, the younger they are, the shorter the wait shall be---my older kids know that the 2 year old gets the first drink poured, ice cream cone made, whatever "because he's little and can't wait" (as well!) I don't think they learn a darn thing through being allowed to be loud in places where quiet is the expectation, or snacking in eating-prohibited places. I have young children. They eat before and after and survive just fine. When we go to someone else's home, I expect them to do things like remove shoes at the door, listen to the adults there and respect their rules for their home. Simple. That said, I just plain out do not take my 2 year old to the library because he's NOT quiet, and I consider that part of GD....don't take them into environments where they most likely won't do well in the first place.
Oh..and if we take toys into a place with lots of other kids, like a playground, we share. They do not HAVE to bring a treasured item into the mix. It can stay home or in the car. But I don't see what positive thing they learn from other kids ending up sad. We make that decision *before* we're confronted with the other child who thinks their treasures look cool too.
I also have found that my own comfort level plays a huge part in how well *they* do....I just don't take all 4 of them places where I'm not confident it's going to go well. They sense that, and it doesn't.
And I just plain out don't do things I hate--like taking more than one of them to the grocery store. I just don't do it. ;) I'd rather have several root canals.
Lately I am happily getting tons of "discipline miles" out of the fact that I control the computer passwords. Also my DD especially responds to natural stuff like "well, you (or you and your sibling) made a mess at dinner, now you (all who were involved) are going to clean it up" She's FOUR, of course I help, but she is there working alongside me before she gets to go off and play. Sure, they have the option of saying 'no' but until they've done that or helped with something, I'm not typing in a password ;)
My other biggest and hardest thing is delivery. These 'edicts' CANNOT be delivered in an angry way. If I'm very matter-of-fact "nope, not now, we need to clean up your mess' it happens. If I'm ticked off and show it, it's a battle.