Leaving aside the massive issue of safety, there is also comfort and dignity. I would feel I had to apply more rules to myself about proper appearance more like I'd apply if I were leaving the house (like no tops for slobbing round that are a bit too big and sometimes can show a bit of side boob, think twice about short pyjama shorts).
I also have a thing about cleaning up after men. So whatever extra work were created by having a male lodger would irritate me more than the same work caused by a female lodger. Probably wrong of me but it would spoil my day.
Again on sexual politics, having to tell a man to please tidy up if he's left the shared kitchen in a state, feels different to telling a woman. You get into the politics of expectations and nagging.
Tbh I could do without it and if I had a decent female applying I'd probably take her as a result.
I say to myself one day it could be my lovely sons having trouble finding a place so am I being awful? Then I think, no, there are plenty of men who need lodgers too and women who aren't as bothered as me. Also a woman I definitely had less choice than the men when I was looking for houseshares when young. So so many places where I was like fuck no, I am not sharing with those dickheads or having that landlord anywhere near me. Viewings were always done with a friend and we fairly often found ourselves doing the signal of that's a no, let's get out of here quickly and quietly no fuss
So on balance I say go ahead and take females only without feeling bad.