JayBEE,
You asked a very important question. I've also asked the same question when I became a brother. Here's my opinion: people who are members of two organizations will never like them both the same. Either they'll prefer one over the other (you know they say one man cant serve two masters); and if they don't prefer one over the other; then they'll always like both organizations differently, because both organizations are unique in its own way.
It is true that some people do not think APO is "real", which is very ingnorant; but at the same time not all APO chapters pledge process is the same

That's probably why some people feel the way they feel about APO. Oh, and as for people who only have signatures in other organizations but not APO...that's because the "social" organizations are still the "in-thing". I mean, APO is a great service fraternity...but some people automatically assume that if you're Greek and not social, you ain't got no game.
L,F,S
PUC'R SP00
Epsilon Nu Chapter