I don't claim to be totally proficient on the subject, but I concur with both sides.
From what I have
seen, many male ABDLs have been rejected for opening up; which is for the exact reason Drifter mentions above -- cultural expectation and types. I remember reading on
understanding.infantilism.org (which I know there are very mixed views on!) about the princess-dragon effect, or whatever they call it... and how men in most cultures have an expectation of being in firm stead, taking on the traditional traits of "manliness"... which aren't terribly synonymous with wearing diapers.
Indeed, in this day and age, no man should be pegged with those traits; in Western Society in particular we've learnt to see past that somewhat narrow-minded view. The issue comes into play I believe because many women have that "traditional" expectation of men -- particularly if it's their partner, wife, etc. who should be the person to look after, nurture and protect them; not the other way round, which would be the connotation brought up by an ABDL lifestyle. Not saying that's always the case, but the first perception probably
is to do with which sex "should" be more likely to assume that role being in a position requiring care and attention.
And that's why it works the other way; because sadly that is still the expectation society has of men, and of women :-(
Based on my own personal experience, it comes down to personality first and foremost. I wouldn't have told my other half unless I was even a little bit sure that she might understand; or rather, accept it without it affecting our relationship. It took me to know her lifestyle, her story, the way she deals with situations, with people... and ultimately her general feeling on the subject, before I could judge how she would take it. But that took
a lot of persuasion on her part as well, to let me know that there was nothing that could phase her feelings for me.
That's the crux of life. Everyone is different, and to say that every girl is cute and every guy is weird for being into diapers is a matter of singular perception.
Don't let it put you off being yourself... you can't please everyone