Sure, not every site needs to run on a highly-available elastic cluster of nodes, but the alternative mindset of actively rejecting this architecture is arguably even more harmful.
A healthy deployment should be able to scale up and down easily, if not automatically. I wouldn't want to be woken up at 3am because prod1 needs a CPU/RAM/disk increase and a reboot, and the users wouldn't like that either.
why wouldn't you cap a free service? imo it's more irresponsible to demand other people keep a thing you don't pay for running just because you happen to depend on it.
Also, any service can have a financial purpose, even if it's "free" for users. This very forum is "free", yet the cost of hosting it is indirectly paid for by being an ad for the company that runs it. HN also famously runs on underpowered hardware that routinely fails to meet demand, but that is beside the point.