No, not at all. Average Joe understands that sometimes you buy a product that looked appealing on the shelf but when you get it home, you find that it's actually not all that great. You might occasionally find someone who will put down video games forever for a crappy game, but not many.
Besides, when someone gets into video games enough to go into a Gamestop or a Wal-Mart and buy a brand-new $60 game, they've probably researched it a bit. You don't spend $300 on a console and then $60 on a game without asking your friends what you should buy or going to several different websites and finding what's popular. And if you're like the average Giantbomb user, well, you most definitely understand that some games are total turds.
Are there really people who preorder games that don't visit enthusiast websites? Outside of the Madden's and Call of Duty's of course. I would assume if Joe Blow cares enough about a game to preorder it's because of either word of mouth or positive hype from games press.
Would that kind of person even realize Colonial Marines is a bad game? Like, it's not completely broken, right? You can pick it up and shoot things. Maybe it's worse than my perception, but it's not Superman 64 bad. They might be mildly disappointed that it isn't as good as Call of Duty, but I doubt that would cause them not to buy other games.
Yes absolutely, but I think it's just as likely if not more likely for a "joe blow consumer" to be turned off from gaming not from low quality games, but high quality games that are too complicated for him.
edit: However you can't really blame the company for releasing the bad game anyway. Even if there was an unspoken rule to only market good games, that would go all out the window the first time any company breaks this rule. At which point it's every game publisher for itself. Which is what we have now.
Bad games can taint consumer confidence in a developer/franchise of several games. Not so bad if the franchise has a mediocre reputation to begin with, but pretty damaging to sales if traditionally strong series has one or more poor releases. Resident Evil, for example, had a strong reputation from RE1 to RE4 and most off numbered games released during that time. Now? I don't think Capcom can bank on a new Resident Evil to sell above a particular threshold.