Non-sales people selling their product - what's the worse you've seen?

For context, a few months ago I met with this guy who owns a company that's created this very interesting solution that could potentially help BDRs and SDRs do a better job with engagement. Just to keep it safe I won't give much details on their solution, all you need to do is they're pretty much in startup mode yet but they're doing great. Already going through Round B and getting some major funding.

The guy, founder & CEO did a fantastic job of explaining the "why" their tool is great, but every single thing after that sucked. It is as if all he did was focus on building a killer value proposition and nothing else. He basically didn't ask any questions but this one: "so do you think we can sign the contract in the next couple of days?" and was met with silence from me and the rest of the people with me in that room, so his follow-up question was "we can even discuss a downpayment" .

Long story short, he didn't sell and instead, we looked somewhere else.

This is not the first start-up CEO I meet and what I've observed is that they usually are not great at selling and just lead with product. Maybe it was just my bad luck, but I was wondering if anyone's had better experience or any thoughts around this?