Precisely. If you chose your product/company name to be a common word in the english language you should expect it to be more difficult to exclude others from using it too. I don't think there's anything wrong with this, it's just the consequence of a non-distinctive trademark.

This should apply for both threads software and meta.

I'm a bit surprised how many people here have sympathy for companies trying to enforce exclusivity over common names. Let anybody use "threads" if they want.