It all depends on your circumstances of joining a professional organization is worth it or not.
You'll finf many people cusring them, some getting benefit from them and some taking about them af if they were selling; "the best widget of the decade that will do everything you want and it's a bust buy at $10 as it's a bargin!"
My view is that some of them are over bloated and exist to extract money out of you. Thing is, thry can't do it blindly so have to provide a service which can be to put you on their books that others needs to pay for when seatching for a professional.
Not that I'm not just talking about about IT organizations. I'm on about all of them! From I.T. to plumbing to whatever.
Don't get me wrong, some organizations exist and to provide an ace service. Like in the UK you have to be Corgi registered to maintain gas appliances, which proves that you know what you're doing.
Something that was recently passed as law in the UK is that you have to be a mamber of some other organization for electricians as it's now illegal to do major electrical work on your own house! Regardless of the fact that one may not fully qualified, or have the progessional membership, but one is more that capable of udertaking the work and doing that work professionally!
Proof of the pussing is that where in a few jobs I've been in now, I've ended up cleaning up the mess made by people why have the qualifications and have the membership certificated. I don't and end up doing the job a lot better. Cleaning up their mess and being pro-active in the roles I'm employed to carry out.
Best thing to is to be honest and NEVER dig a hole that you can't get out of.
Now this I have encountered. Meeting people that are I.T. qualified and on some occasions members of the British Computer Society. I ended up whooping the people I met on knowledge and on how-to and how-can conversations.
To me, membership of organizations arms you wish steel-toe-capped boots so you can keep your foot in the door when it's being slammed in your face without any pain to ons self, but then it boils down to; "can that person do the job or not?"
Some can, and do the job very well, and some can't. They make a balls-up of what they are going. Then again so can people who don't have the bits of paper and certificates.
Bring back thew old days where you are given a set of perplexing on-the-job problems to sort out as part of the interview process and it's down to how one solves the problems that determines if one gets the job or not.