Filtering the tells in that way is no different from the blacklist.
That video isn't the same 5 people sending me a tell, that is seriously 50-60 different accounts spamming messages. Blacklisting them is useless since they just delete and recreate a character.

There needs to be an accept tells from friends only option.
Also they really should change something about the sent friend requests issue. Probably limit it to one a minute or so to ideally curb that annoying "advertisement" technique.