The atmosphere, the pretty girls to look at, and the enticing possibility (in their imaginations, mostly) of having sex with those pretty girls. If you go out to a bar, there's a non-zero (but pretty close to zero) chance of getting laid. If you stay home, that probability is exactly 0%.
So what normies do? They dress up, psychologically pump themselves up, and then go out to "GET PUSSY," only to spend waste time and money feeling like an absolute loser and clown (for all of the red pill jestermaxxing they probably learned from video) and crawl their drunk asses back home and then fap themselves to sleep.
Rinse and repeat every fucking week until success or suicide.