It does indeed appear to be their strategy; although it seems to work well enough for them. It's just a bit frustrating for users who periodically lose an app they came to depend on.
Does it work for them, though? I don't remember their successful products arising from this process; they never had a bunch of email services before Gmail, nor multiple mobile OSs before Android, nor different browsers before Chrome, etc. The closest might be Google Video before YouTube, but it wasn't really the same kind of product.
Their strategy seems to be throwing stuff at the wall and trying to get something to stick.