I went to a few meetings of my oldest DS's secondary school PTA. I found a lot of the stereotypes mentioned here to be, sadly, true.
Lip-service was paid to welcoming new members but the new faces seemed to disappear one by one - including me, after struggling on for five or six months.
The unspoken (or sometimes actually spoken) question which hung in the air seemed to be 'what can you do for us? ie perform some sort of useful function for the committee (financial management, marketing, poster design/artwork etc.) I didn't feel qualified or experienced enough to volunteer for any of those 'leading' roles, but was perfectly happy to give assistance as required, and to turn up and help at functions as required. Apart from helping to set up and man a stall at the Christmas Fare, which I knew about through having been at the previous meetings, I was never contacted to help out.
They have spent £27k over the last year, it seems, which is fantastic - good on them. I just think the underlying feeling that if you weren't pulling your weight directly for 'the committee'' you weren't welcome and your comments wouldn't be listened to.
£10k was spent on a 'fourth IT suite,' which, maybe I'm mis-guided, but I didn't see as a PTA's remit to provide. Whereas the pupils have been promised lockers for several years, which have yet to materialise. It also emerged that the PTA chairman had previously arranged to remove a lighting gantry from the stage in the main hall as it interfered with the room's aesthetics (wtf?), so now there is no lighting for performances.
Teachers were put through hoops to get small requests accepted; eg a washing machine was requested for the PE teachers to wash the first teams' shirts - having used their own previously. Much rubbing of chins ensued. However, when the deputy head mooted her £10k request for the IT suite, it was treated as a no-brainer.
As I said, your opinion wasn't welcome if you weren't one of the main members - hardly democratic, but then I suppose there are no rules to this - that's part of the problem.