I have not yet seen anyone present a good reason for having an alt account. So far, every alt account I have become aware of has existed for nefarious purpose.
Ignorance is not evidence. The fact that you are unaware doesn't mean they don't exist.
This is quite true. Leprechauns, vampires and mermaids may all exist also.
Perhaps you could consider this an opportunity to present a reason for why it would be good to allow alt accounts. By "good" I generally mean for the society as a whole, as well as the individual.
Do you also think that people should be required to register their bitcoin addresses? After all, there is no good reason for anonymity. Bitcoin is only used for buying drugs and funding terrorists.
Not sure why you brought this up. I don't recall taking a position on any of these topics. I don't really care to now since they don't really apply to the topic of this thread.