You know, they may be a little silly about it, but this really isn't THAT unreasonable.
In theory, Petitioners all buy Sonic 1. Sega looks at sales numbers. They see that Sonic 1 sells a bunch after the sonic hype, Sonic 4, not so much (Of course, this is assuming that they get anywhere with this). Sega says, "You know what, I like money. Old school style games seem to sell a lot better. I guess that's the road to more money". This isn't insidious fanboy stupidity. That's free market capitalism, its how every other franchise that succeeds or fails does it, and it involves the complainers trying to encourage a developer in positive ways instead of just kneejerk punishing the developer who committed a perceived wrong. Frankly, their methods and approach are commendable...
...but there opinion is silly. Come one, that looks to me like a return to the glory days of Sonic, and Sonic Rush was a really good Sonic game, true to its traditional form, while adding its own flavor. The fanboy stupidity is not from a poorly executed boycott; They "Boycott" idea they have is sound. It's from fetishising the past so much that they can't see the fact that there getting exactly what they want.