Is it a good idea? The answer is probably "it depends"... if you're looking for a romantic partner who will join in with you, then at some point you're going to have to have the "I like this" discussion. Try framing it in the context of a "what fantasies do you have?" discussion, and take it from there. Just keep in mind that not everyone is going to be okay with diapers. If you haven't already, you might want to try writing a personal ad either here or on a DL-specific personals site. The advantage to meeting someone that way is that they're at least aware of your preferences, even if they're not massively into it.
If you meant "should I tell my friends and family", I'm firmly in the category of people who don't do that. My personal life is my own, and this side of my personal life is something I'd only share with like minded friends or a partner. I just don't see that anyone else needs to know, and knowing how bad I am with words if I ever did try to explain myself I'd probably get all tongue-tied.
On your final question, if you tell someone is it possible they might go on to like you? Well again, that depends on the person. If you're dealing with someone you're interested in who isn't from the DL or cg/l community, it's unlikely that confessing your fondness for diapers will increase your chances, let's put it that way. If you're already involved, you have to put yourself out there and hope for acceptance. I wouldn't suggest you hide it from your partner, because lies in a relationship can be toxic.
Good luck