Yeah, it's extremely hard to get to a serious scientific discussion when field of "ufology" is so filled with grifters.

The main problem I'd see with CSICOP isn't dismissing alien visitor out-of-hand but rather tarring ideas that are merely unusual with the brush of crankdom - for example, I think Martin Gardener was attacking Alfred Korzybsky long ago. I'm not a Korzybskyite but I think his ideas are in no way tied to any super-natural or extra-scientific assertions.