Maybe you don't rationally need someone to talk to when someone is fixing a problem for you -- but I think you need to know that the vendor is _aware_ of the problem, and is working on fixing it.
Or you start freaking out. And I don't think that's entirely irrational.
This is, among other things, why the 'post mortem' has become somewhat popular -- because it allows us to judge "Yeah, those guys DO know what they're doing, they're on top of things, the chances of outages are getting constantly smaller, not larger."
Has Google ever published such a "post-mortem" after an outage? Has Google ever even admitted there was an outage publically?
But also, yeah, rational or not, people like to have someone to talk to. In customer service in general, there are many studies showing that customers satisfaction will be higher when they are treated 'nicely' _without a solution_ than when they are treated brusquely but their problem is solved. This is not actually rational, and I'm not saying I'd like vendors to strive towards that model -- but it is apparently human psychology that vendors may want to take account of.
On the other hand, Google seems to be doing pretty fine how it is going. Although I don't know how GAE is doing, really, compared to competitors.
How Google does it, though, is basically no support at all, right? It's beyond 'good support' or 'bad support' -- with the possible exception of AdWords, is there any Google product where you can ever talk to a human about any support issue at all? For email that might be fine, especially when the email product is pretty darn reliable. For enterprise critical software... it would sure make me nervous.