> a lot of real world applications where small amounts of data loss don't matter but latency matters a lot.

I don't understand this reasoning. We are talking about defaults. Defaults are used by people who did not tweak the settings yet. If I am just starting building a thing, I will have bugs and squeaks and I want to make sure I am not fooled by some unreliable data store. I am not likely to need 100GiB/s throughput, but I am very likely to have to hunt bugs, like "I did click on this <like> button but it did not add to the total likes". And I would really really hate it if after half a day of bug hunting I would realize that my data store just didn't store the thing...