[jeffshek]

I suspect the tech stack was merely the 5th or 6th reason for not funding, they were just looking for a way to move on.

If they were reasonably interested, VCs won't say no - they just pretend to not see your emails until someone is about to lead a round.

[smackeyacky]

This is the most likely answer. There would have been a few other warning signs durung the due diligence but most VCs who have rejected me have used some incredibly lame excuse instead of being honest.

It wouldn't hurt them to simply say "we don't understand this and that makes us uncomfortable" instead of bullshit like "doesn't fit our investment profile" or the tech stack is wrong.

Trying to educate VCs in something out of their comfort zone is like trying to teach a pig to tapdance. Most of them I have had dealings with have such limited life experience they will never really understand agtech or biotech.