The difference is that people who complain about these upvotes don't have a vested selfish financial interest and aren't marketing anything to us. Unlike the Bitcoin pump-and-dumpers, they are exercising judgment rather than trying to manipulate others.
The statistics here seem more important than the individual cases. Not everyone who talks up penny stocks is long them either, but most of the people sending spam promoting various penny-stock pump-and-dump schemes have a selfish financial angle in doing so.
I'm not saying there's no reason to be interested in Bitcoin other than personal financial motives. The technology is legitimately interesting, but not nearly enough to have gotten the marketing push that it's gotten, particularly here. Only one thing explains that: the selfish incentives that the current implementation of Bitcoin provides. (Well, or extremist ideology.)
