You can simply not use it, no?

I am not going to make any sweeping generalizations across all products. But at least in the case of Deno KV, there doesn't seem to be lock-in. So if you were running something self-hosted for KV persistence, it will continue to work unmodified.

> I would see with disgust a bunch of startups use "open source" as their marketing tactic.

Again, not sure which bunch of startups. But I am not seeing that with this product. Seems more like a survival strategy to add some cashflow behind the developers.

I am curious what you think Open Source should be (or should not be). I think it's fair that running a service in the cloud should cost something. And self-hosting it, I think it's fair that it requires a bit more effort than using the hosted service.