I wonder if this has anything to do with wearing gloves:
http://news.bbc.co.uk/1/hi/england/northamptonshire/7770904.stm
http://news.bbc.co.uk/1/hi/england/northamptonshire/7770904.stm
Would you be wearing gloves in a self-defense situation?
Your logic for not training with gloves because you probably wouldn't be wearing them in a real life encounter also goes for ear plugs.
Even when its cold out, I use pockets to keep my hands warm.