It wasn't unilateral (assuming a definition of "unilateral" similar to the English-language one). I can personally assure you that there were others working with me.
There was plenty of support for removing them, so it was far from unilateral. Whether or not there was a consensus is questionable, but there was certainly a large amount of support.
The matter wasn't helped by people not reading the articles carefully before removing tags, though - for example, I had to replace a spoiler tag *twice* in a particular article that was in the Cast section just before it was mentioned that a member of the cast had left following the death of their character. A Cast section is most certainly not a plot summary or anything similar - if it is ever right to use spoiler tags (and there most certainly is *not* consensus to remove all tags), then there should be one there.