I'm inclined to agree with you.
I'm as entrenched as anyone could possibly be in the Google ecosystem, and it's not because they're force-feeding me their products. I frequently try alternatives when comes to stuff like online calendars, documents, email, whatever.
The reason my attempts to use other services never stick is simple: they're just not as good as Google's offerings.
I can kind of see where they're coming from if Google is in fact promoting their own services in their search, but I suspect that their own algorithms are picking out their own services because the most people use and talk about them...again because they're just the best offering.
Personally it's tough to sell me on the idea of a provider of free web services getting into antitrust territory, because a different search engine is always one different URL away. The same goes for all their other services. It's tough to even call them out on vendor lock-in, because thanks to the data liberation front they're one of the best companies I've ever seen on the internet when it comes to avoiding lock-in.
I'm dubious.