Where there are a plethora of members of the opposite sex, you give yourself the greatest exposure.
When you attend an event at a location where there are plenty of women attending, there are more opportunities for you to be seen by them, which increases the likelihood you find a date.
This is intimidating to some guys.
Putting yourself in a social venue where there are a bunch of girls is nerve-racking when you aren’t used to being in these type of venues.