Marc is extreme smart and talented individual. But when your on Twitter 24/7 and keep on making predictions your gonna be wrong at times. Sometimes you can be wrong in a really big way.
I haven't seen any evidence that he's particularly smart. The guy had an early success that convinced him he can see head and shoulders above others. This turned him into a write-only visionary. Like many such people, he's entertaining to read because of the strength of his convictions, but it's probably a bad idea to take him too seriously.
I had a discussion with him around inherrent value in currency btc, fiat etc and I was actually quite surprised at how unreflected his view seemed to be.
But I would still consider him a smart guy just not a clairvoyant.
He's been prolific in starting and backing a huge number of original ideas and companies—I'd say the market is giving him all the feedback he needs that he's doing something right.
It's a good advertisement for Marc and it serves a marketing purpose of continuing to get him media exposure which is good and keeps him on the radar of entrepreneurs and other VC's and burnishes his image more in the media. So he ends up getting more exposure.
Business wise of course he doesn't have to be right all the time obviously only right enough to have some big scores. Besides people rarely do follow ups detailing the missed predictions and even if they did they would mention the successes that made up for the failures and how that's kind of the VC model.