Oh yes, I have been involved with several RPGs that the GM used for more of a toy. I have also been on a few that the GM really didn't care about the game at all. Either way the reality of the story line simply stank. Even some good GMs on the other hand have a hard time with convincing motives though. In most cases I simply sent in a request to resign from the game and let him simply kill my character off. Others, one in particular, I was playing with a good friend of mine, and for some reason no matter how dry the GM left the scenario we just stuck in and found an amusing way to bring on a completely twisted chain of events. Burning the general store down at night and killing a bunch of squirrels to leave in the road. It was completely stupid so we simply acted the part and had a blast.
Being a GM tends to be a very broad job with a lot of duties, and sometimes creativity does not flow like a waterfall. I can suspend a lot of my desires and needs, as a player, for compelling this or that, if I can get the sense the GM is trying, or that if we take this or that for granted, that the plot and characters will flesh out eventually. Depending on the scenario, sometimes "generic" NPCs are a blessing, as you can develop them yourself, as players, if the GM allows, and they can be far more interesting than they might have been otherwise, and may even rise from the ranks of generic NPCs to contacts or recurring characters (maybe even villains).
Oh yeah an its really annoying. If you're going to have a good scenario then it has to make sense to me. I've been some scenarios where the DM made everything happen like the town people were looney the monsters were on drugs and the dungeons like an amusement park.
I have had more than my share of DMs who really did not know how to me a DM. I was at one point able to take out a group of goblins with just one person by making the DM believe that I had the powers to do it. It made the game no fun. One must have fun in the game in my opinion.
That sounds like you manipulated the DM and it wasn't his fault. I really have to keep my eye on you guy . Seriously though you're right about the DM knowing what they're doing.