I think that for many of us, it's very similar to how it must feel to be a gay person who wants to come out but hasn't yet found the courage to do so.
Being seen in diapers gives many of us an incredible rush, and I think it comes from the conflict between two very strong feelings:
1) I wish everyone in the entire world knew that even as an adult, I love wearing diapers.
2) I'm scared to death that somebody will find out that even as an adult, I love wearing diapers.
I think for many this goes back to when we were young kids and were made fun of for still wearing diapers, while secretly knowing that we loved it and never wanted to give them up. In my case, one incident stands out: I was in first grade and after witnessing several incidents of the other kids wetting / pooping themselves, decided that I wanted to experiment with this myself. I was already very much attracted to diapers, plastic pants and diaper pails (see my other posts). I had a playhouse shaped like a big rocket ship in the basement and would hide in there and wet / mess my pants. Sometimes I'd stuff in a towel and pretend that I was still in "diapers".
I made the mistake of sharing this secret with the kid across the street--who then blabbed it to the rest of the neighborhood. One day I heard a big commotion going on outside and went out to find about half of the kids in the neighborhood standing out in the street in front of my house laughing and pointing and yelling "HA HA HA YOU STILL WEAR DIAPERS!" I remember being embarrassed, humiliated, and strangely, warm, weak in the knees and very excited (a feeling I'd later recognize as being horny). Also very satisfied, in a weird sort of way, that everyone knew so I no longer had to go to so much trouble to hide it. So, part of why I like being seen is that it allows me to experience that same feeling again now that I'm old enough to understand it and enjoy it.
In general, I don't get to go out diapered very often, maybe I get a chance to once a year. But when I do I only want to be noticed by one group--middle-aged women who look like they are probably mothers. MILFs, as it were. I try to avoid being noticed by other men, and I do everything possible to not be noticed by kids. (My favorite time to go out diapered is on a weekday morning when the kids are all in school, around 9:00. I never see any kids, very few men, but I do see lots of women who look like they've just dropped off the kids and are now doing the morning shopping.)
Usually when one of them sees me, they get this surprised look of "I absolutely can't believe this!" along with a silly grin on their faces. This gives me this incredible sense of humiliated exhilaration. No, I don't think that women who see me in diapers will ever want to engage in diaper play (even if they did, it wouldn't happen because I have a wife). I do think that--while many are absolutely disgusted by the idea of a grown man in diapers, others are turned on by it (my wife is!). Some just think it's laughably hilarious. Many of them probably think that all men are just a bunch of big babies, anyway, and this just confirms it. Not to mention how some of them probably like the idea of being dominant in a relationship and there's no better way to do that than to put the man back in diapers!
So on those rare occasions when I go out in mine, I find myself putting myself into increasingly more "dangerous" situations while making my diapers increasingly obvious--UNTIL I know someone has noticed. At that point, I've achieved my goal and the go home, reenact it in my mind, and get myself off while enjoying the humiliation. I think about that look on their faces and imagine them thinking about what a big baby I am, and how at that very moment they're probably telling all of their friends "You would not believe what I just saw!"
And no I don't think that by doing this I'm "inflicting my fetish upon others". As long as I have on shorts or sweatpants over my diapers, I'm not doing anything illegal. In public you're going to see some interesting things, and nobody is forcing them to look. And most of the people that see me--even if they find it amusing--will eventually decide that I'm wearing them because of incontinence and likely feel guilty for thinking it was funny. They'll never know that I was doing it for fun!