In general, homosexual "men" aren't any lonlier than other peope, they are just more willing to have sex with strangers, or rather men they have just met. I have known a few homosexuals and had one tell me that he preferred sex with men because it involved no commitment, no wining and dining, no romance, no nothing other than just sex. That is their chosen life-style.
Older homosexuals are lonely if they do not have money to buy the "company" of other "men".
As to people assuming someone is homosexual, women may ask you as they don't wish to catch AIDS or any of the other STDs that are prevalent among homosexual or bi-sexual "men" and who can blame them? Homosexuals ask because they hope that other men are willing to have sex with them. Yuck.