I always deleted them, but by doing so I concentrate on them even more I noticed. I find it a weird feeling to have players who don't live anymore in the database, yet the database is so comprehensive that in every earlier football manager version some are probably dead around the world.
This way, I guess it is better to accept it and realise it is a game and just play it. I have thought about starting with fake names in earlier versions, but that doesn't really work. It isn't as fun as with the original ones.