Peter Fenton invested in the company when it was called Infra.App originally (I think it's still online: https://infra.app/). It was an access management product, then it became desktop Kubernetes product, both they pivoted out of. I imagine he invested based on the technical acumen of the founders and then worked with them to pivot when Ollama started working out. Almost all of the other investors invested in the founders based on that original idea space (which wasn't a great one but was quite adjacent.) I think that includes 8VC, YC, Pace Capital, GTMFund, who all followed on here.

Since it pivoted, I imagine the story they are telling is the usage. But you can add to that Peter Fenton has had incredible success in commercial open source (Docker-ish, Elastic, JBoss, CockroachDB, TimeScaleDB, and if you include Benchmark there is Elastic, Confluent, etc.) so a bunch of these people are probably trying to ride the Peter Fenton/Benchmark train. My guess is that's what Theory is doing.

Investors are not free but they are very hype driven. There are < 10 investors who are truly experts in open source in my opinion in the market (and maybe < 5.) It's a really wacky cadence and I would argue there are different types of OSS businesses, which makes it even more difficult to be an expert. It's something I struggle with personally investing in OSS -- I think I understand the likely motion for an OSS startup and then > 50% of the time I am wrong.