Teaser trailers feel dumb to anyone who isn't surprised by them.
But if you didn't know anything was coming (like most people) then they're something to get excited about.
If you read this thread constantly it feels like you've spent months discussing the same thing, because you have. But for everyone else they just get a few days to speculate and build interest before the full trailer drops.
The world is jam packed with distractions, people are tuned into their own bubbles, and tuned out of everything else. It's hard to reach them. A company like Stern has to fire as many shots as they can to try and get noticed.
Winchester selling out or Beetlejuice selling out is because they're small runs, aimed at a small and highly specific audience. Stern aims for far beyond Pinside.