The real exceptions are the ones with massive bot networks. I've seen more than 10,000 accounts with the same URL in their profile.
That wouldn't happen in my scenario.
That sounds like extra work for Admin.
Not much more than changing a name from time to time.
So do all of you think that we shouldn't declare our alt accounts? Am I the only one who believes that it's indeed better?
I don't see why. Whoever wants to declare it should do so, and whoever doesn't should not, as explained above.