I don't think it is this simple. The volume of players for each role makes Survivors a priority, but also the questions for Killer need to be smarter because problems are sometimes very Killer-specific.
Was the last pure killer improvement EGC?
Fix maps for Killers!
Critically, in the recent player satisfaction surveys there were no questions about why Killers might find the game unsatisfying. Only Survivors.
No wonder they're only presenting data on camping/tunnelling/slugging and not on Killer issues... they're not asking.