First, Player's Handbook 2 sold nearly as many copies as the core, something splat books never do (we can argue I guess whether or not PHB2 counts as a splat book, but it pretty clearly does). So while some people bought the core and then abandoned the system immediately, we're not really talking about a significant number here.
Comparing players 2 to say complete divine or complete arcane is dishonest. 4e's business plan was different from 3.5- that edition had splate books, while the 3 main were core. 4e's plan was everything was core, so they spread the core choices out. No suprise folks bought it.
So no, its not a splat book.
Second, liked we've discussed, this perception of failure only exists on sites like EnWorld. And if you've seen this negative perception elsewhere, as we've established, this is because no matter where you go, you're bringing these perceptions with you, so there they are. I guarantee this perception of failure just doesn't extend to mainstream consumers. The only people that are aware of the so-called "edition wars" are its participants.
Well here, other forums and apparantly Hasbro board rooms. You're ignoring the fact that 4e only lasted barely 3 years, then essentials came out, and now is abandoned for 5th.
I'd bet it expands farther then you give it credit.
Now obviously, WotC doesn't want to alienate its most devoted customers (those so few devoted that visit sites like EnWorld) like it has in the past.
Unsupported. Wotc has in the past and it may do so in the future. You can argue the open playtest shows it "supports" us, but on the other hand, WOTC's track record doesnt show that at all as of yet.