I am a life member of both my state orgs, and members of several other states and national orgs. Joe hit the nail on the head when he said about "getting more involved" if things don't go your way...and they sometimes will. But I've seen many orgs take new direction from as little as one concerned voice with the courage to stand up and make a case.
In this day and age, there are so many orgs to choose from, it's important for folks who wish to get the most "bang" for their buck, to do their homework. Find out if an organization is legit, if it has "other" agenda's, where the money is spent, etc. etc. Most state orgs exist to safeguard YOUR opportunities, and they usually are the best place to belong, especially if one has to choose.
Also, in this day and age, being active is paramount for us to hold on to what we have. There are plenty of pressures out there today affecting our opportunities...just choose something that you have passion for, be it equipment, or habitat, or education and get pro-active! And don't worry about the folks that always whine...they will still be there regardless. And I've always contended that if you are not pi--ing someone off, then you are not really doing anything. Just do it.