I don't understand why this sort of thing happens. At Intel, I got the silent treatment after getting an offer. It was for an implementation (RTL -> circuit) position. We chatted about schedule and it was apparent that they wouldn't actually have a pressing need for that sort of thing for at least six months, and that they were hiring as they could and they expected to be hiring implementation folks for at least another six months to fill all of their reqs.

When we got around to discussing start date I asked if I could take a few months off between jobs and start in a few months. The hiring manager (who was an engineer, not a recruiter) stopped responding to my emails and returning my calls. Months later, I asked a friend of mine what happened and was told "X is busy". Too busy to spend five seconds responding to an email? Really?

Today, that hiring manager is at ARM and I declined an a chance to interview in his group when I found out who was in charge. I think I dodged a bullet; I can only imagine what working for the guy is like.

By contrast, I applied for a job I was completely unqualified for at another company around the time I interviewed at Intel. I didn't expect to even get an interview, and I didn't. But I still got a nice snail mail rejection notice. Many years later, I now work for that second company.

Like I said, I don't understand why this sort of thing happens. Putting aside kindness and basic human decency, even if you're completely selfish, it costs basically nothing to be polite, and the benefits are pretty large. Conversely, being rude gains you nothing and has noticeable costs.