Comparing pre-ordering video games to pre-ordering supermarket food is pretty stupid. Video games are not perishables.
And it's not like the video games industry is the only one that does it. I pre-ordered my car. My wife has pre-ordered books. Pretty much everyone who has backed a kickstarter project has pre-ordered something.
There have been dozens of games that never got released because the developer run out of money, or the publisher pulled the plug because it was costing too much. Like it or not, making video games costs money. Pre-ordering not only shows to publishers that there is a demand, but can also make sure the developer doesn't go bust before release. Yes there's a good chance we're putting our money into a broken, bug-riddled game. But let me share you a secret - everybody knows that. If the developers show no intention to fix it, we still have the right as a consumer to get our money back (the 'not fit for purpose' rule is a good one).
Where you should really be directing your anger, as far as the video games industry is concerned, is the plague that is micro-transactions. Buying the game, then having to pay more and more just to be able to play it. Games like Payday 2, where you buy the game only to find that you have the barebones unlocked and you have to pay more to unlock weapons that were already shipped and installed in your copy of the game.
Also:
"My recommendation for all computer games: Wait at least a few days (better probably a few months), check the forums,"
Well, if everyone did that, the forums would be pretty blank, wouldn't they? How would we ever know that the game is stable or broken if nobody buys it?