Everyone has a type. Sometimes its not the stereotypical standard of beauty. Lots of men like curvy women. Some like fat women. Some think personality is more important. In general i think most men are better looking than most women and there not half as fussy as we are.
Im not sure why you assume hes insecure for going out with someone "who wont get hit on".. some ugly women get more attention than the best looking girls I know coz they go looking for it more. Have you ever watched jeremy kyle?? Some of them are uglier than a hippo but have slept with 200 people.. and have 2 men fighting over her on stage.. lol..
Just coz someone is unattractive (to you) doesnt mean they are trustworthy..
"Don't ask a question if you can't handle the answer".