They put a lot of study into hyped categories, so they at least understand the businesses they're investing in. They can evaluate the caliber of talent, understand the depth of your moat, etc. Whereas with businesses outside of the hype (or outside of their specific specialty) they're not confident in their ability to even evaluate the potential of an investment.

(I'm working on a startup right now that's in a similar position - non-hyped B2B segment. VCs are all "hey, look, we don't understand X market very well, maybe go to Y VC?" And Y VC is all "hmm, you're only tangentially related to Z market that we actually understand, so you'll need to get to Series A-sized revenues before we'll put in a seed-size investment.")