[Original quote and reply to that quote deleted by Moderator to conform to Moderator edit of quote.]
Pax putting smaller bags in the overhead bin takes away valuable space from other pax - this is definitely an issue across the board (not just UA). It's been so bad, on more than one occasion, I have witnessed first hand (as a pax in the bulkhead row), FA just turn the blind eye when 5 of 6
pax have their bags in the in front of them.