If a group of say, 10%, is responsible for 90% of a problem, it says something about that problem that probably relates to something specific going on in that group.
Current mass shootings appear to be committed by whites in a proportion equivalent to their overall proportion of the population. Meaning around 70% of shootings are committed by a group that is around 65% of the population.
This doesn't demonstrate there is a specific 'white male' problem. It does demonstrate there is something unique about males that overwhelmingly make them responsible, but it seems likely there is an affliction that causes problems across race, regardless of race.
Perhaps there are, in fact, 'white male' attributes specific to them, but you'll need more statistics to demonstrate something which even suggests clear causality.