I'm not sure if I understand what you mean, but there are a lot of people working in the engineering department addressing the problems according to the telemetry data - and if the team bosses official party line would consistently somehow be against the data, I don't know how long they would be able to keep the sham up. There are investors to report to, constant changes in personnel and also lot of internal competition inside the team, so the truth would eventually creep out. By constantly lying about such a thing the bosses would make a lot of people unhappy and it would in the end in a normal situation cause a lot of harm both inside and outside the team.
Let's just say I trust official team statements not as much as you seem to do, particularily not in difficult circumstances.
But isn't what Schumacher has said just the same that you remember Alonso has said? Surely MS has said "he's working on it", only with the exception that the tire supplier wasn't about to change in 2008, so Alonso couldn't say "hopefully the next year's new tires work for me better", which I'm sure Alonso too would have then said at some point?
To be fair I don't recall MS himself to complain too much abiut the tyres, I was referring more to Ross Brawns and the fans.
Furthermore I'd be cautious with the expactations regards "star" drivers - there really isn't any way to determine what a driver "should" be able to do in a certain situation, because the cars, tires, teams and yardsticks constantly change and every season becomes a different situation. Except a blanket statement that the "stars" should prevail against their team mate regardless of the situation. This in turn I'm certain is false to begin with, as any star driver past or present would get beaten by a teammate considered "lesser" in a legitimately "equal" situation, if the cards that we can't see stacked up against them just right. That's the unfortunate nature of the current motorsport formulas.
By "star" drivers I mean the very top, and to me those are defined, among other things, by being able to extract the max under any sort of circumstance, which MS (evident by Rosbergs better performance) isn't able to anymore. On it's own, I perfectly sympathize with a driver mourning unsuitable equipment, but that only goes so far. In the end the results count and if they aren't forthcoming, tough luck, time to move on. To give two different examples, I think both Montoya and Räikönnen are more talented than what they're final stats suggest, but in the only reality available they weren't able to exploit it fully, and that's that. Nothing anyone can do about it.
Same goes for MS v2, he isn't able to deliver the max with what's available, and pinning ones hope on completely uncertain tyre charateristics in 2011 sounds pretty desperate to me, at best it's a bet with not too brilliant odds.