I rode 65 miles and climbed 6,000'' yesterday in the Santa Monica Mountains where lots of experienced roadies go. I waive to passing cyclists most, but not all, of the time. I won't necessarily waive on a steep climb if I'm concentrating on my breathing, or on a descent if I'm going fast. I can't say that I came across a single cyclist that came across as snotty or arrogant, and I probably encountered hundreds. I find the vast majority out there are friendly, but like anywhere you go, not everybody wants to socialize.