I don't understand why this is so hard to comprehend. Google runs a business in direct competition with Exchange. It's business mail service is one of its pay services which it's actively trying to sell. Bundling in a built-in client for Exchange that is better than their GMail client isn't going to be in their best interest.
Saying that the N1 is somehow fatally flawed for missing an application that's not only easily available on the market, but also works better than any other Exchange sync app on any phone I've used is what I don't understand. Complaining about the 3G coverage dropping, or that it's on T-Mobile and therefore doesn't meet your needs are valid complaints to why the N1 is a poor choice, saying it's a poor choice for this reason is just silly.