Not necessarily, but it makes you sound oddly defensive, about something that actual "nice guys" don't normally feel the need to self-proclaim.
Ahem....right. Why should you even need to "convince" anyone...SAY that you are a "nice guy", if you indeed ARE?
Well no, you didn't really answer my question. I'm sure I didn't say anything about "worthy" people, either. Most of the time when a person doesn't think another is very "nice", they have a pretty good reason for why they think that. They might change their minds, but it sure wouldn't be because that person told them, or proclaimed themselves to be "nice".
Not really. Based on past experience, I believe there are many reasons why someone wouldn't "allow" another to be nice to them, that have nothing to do with any insecurities or anxieties. I also think people have varying ideas about what being nice is.
This question, however, is about those who "self-identify" as being nice. If the OP means those who for some reason feel the need to often proclaim themselves to be...I've already said what I think about that.
As far as your question, I could only answer it as to how that usually feels wrong for me.