I personally, don't think that a man not serving a mission makes him less of a person. My sister is getting married to a guy that was 20 when he was baptized into the church, a mission just isn't for him. He already had his life planned out and was getting his education. I wouldn't have a problem marrying someone that didn't serve a mission. Although it depends on the reason why he didn't serve a mission. If you were just lazy and didn't serve a mission when you turned 19 then I would have a problem with that. But your 21, and you have other plans. So I don't see why someone wouldn't date/marry you just because you haven't served a mission. If that's their reasoning, they aren't worth it.