Problem is, the situation with the games industry is a different market than for any "consumable" product you can name. Take, for example, detergent. You have a few name brands - four or five, maybe more, I don't really know. You have a bunch of outlying brands, with store or minor names. They aren't as well known, or as popular. Thing is, they're all making detergent, and if one brand tries something outrageous, it's not hard to switch to another. This keeps the producers in line.
With games, it's different. The games industry isn't catering to one consumer base - it's catering to dozens of different groups that like different things. A lot of the time these interests cross over. But each product is sold to a market category - say, the people who like military shooters.
Thing is, games are a lot more differentiated within their market groups than comestibles. Where the difference between soaps may not even be noticable, the difference between an AAA- and a B-list game, in terms of polish and support; and crucially for many people in terms of the multiplayer pool, is huge.
The games industry is a collection of monopolies. There tends to be just one person sitting on top of a given genre, a given market, with everybody else crowded around at the bottom trying to whack him off. This is ESPECIALLY true of the mega-sellers: Call of Duty, Halo, and World of Warcraft each dominate their respective field. And it's a lot easier to knock off the leader of a singleplayer market than that of a multiplayer one - take the MMO field over the past 6 years as an example.
Sometimes, as with the competition between Guitar Hero and Rock Band, a real market develops. And, as with proper markets in other industries, the competition has kept Activision more honest than otherwise. Customers stopped buying the dozens of Guitar Hero clones that they've shoved out the door recently. I count fifteen core games in the Guitar Hero series, thirteen of them made in the same period that Harmonix made just six. The customers have a choice here. And they're choosing, and Activision is hurting. They're going to change their business model in this area, or they're going to lose.
To summarize (with added spice):
Call of Duty is an example of what happens when a series gains a genre or market monopoly: A field day of profiteering.
World of Warcraft is becoming similar. Activision are masters of profiteering, and they will do so wherever they have influence.
Guitar Hero/Rock Band are an example of an open market killing a profiteering attitude.
Now, I expect that Call of Duty will soon be dethroned. Medal of Honor is a serious contender, and depending on which way the reviews swing, it could establish itself in the same position Harmonix' series holds. Similarly, the prior Infinity Ward presidents could knock Activision's cash cow off its perch - all it takes is a worthy alternative product within the same genre/market to get the rats to leave the ship.
And when Activision's cash cows are down... there follows Activision, and its scummy CEO with it.