Is it true that a PTA is only interested in driving funds in their pockets and increasing membership?
Well, put like that, I'd have to say no--they're not ONLY interested in that. But they are interested in that--just like a PTO is interested in raising money and increasing membership.
Many people will tell you that at least part of the reason that they are PTO is because all their money can stay within their school. With PTA, part of the dues go out of your own school to a local, state and/or national PTA. Those monies are used to fund certain programs, like Reflections (arts program), and advocacy/lobbying efforts, among other things. Some people decide that those monies that go out of the school are very significant to them, and they do not get enough benefit from them. A lot depends on how active your state PTA is and how interested your officers are in advocacy issues. MichelleB, someone who posts a lot on here from Nevada, seems to have a very active and supportive PTA in her state, with some great programs. Others can't even manage to get their state to provide them with membership cards for their members, let alone any reasonable amount of support.
And one example on programs--Reflections is a great program, but how many people actually participate? At least one school in our area last year didn't bother with it because they couldn't get anyone to run it. And many of the others that advertised the program had very low participation (as in less than 5%). So I wouldn't join PTA just to be part of Reflections, for example.
PTA units can be much more structured and rigid than PTOs. Your state provides you with a set of bylaws, and you generally can't change them too much. In some cases, that may be good--every now and then on this board, you see some cases where PTOs have struggled because of bad or no bylaws; some structure might have helped them. On the other hand, setting up bylaws isn't necessarily brain surgery--many schools can and have set up very good structures that give them much more flexibility than PTA, and work well for them.
As for advocacy--some people say that they don't agree with the positions National PTA supports--vouchers are a good example of a controversial topic--and that's why they don't want to be part of the PTA. But I think most parents would support the vast majority of the positions they have taken. A lot of PTAs gloss over the advocacy stuff, though--if you want to find out what the PTA supports, you need to dig around on your own. I've seen very few PTAs who make it a point to publish PTA positions on different things to their local membership, which is another reason why people don't think it's worth the money. I would be willing to bet that most people who belong to a PTA could not tell you what positions their state or the national PTA has on many issues or candidates, and therefore have no idea what their money is supporting. So do they allow their money to go there because they just blindly trust that the PTA will do what is best for them? Yes--you would be amazed at how many people that applies to.
Anyway, to set up a new PTA, I'd want to know exactly what benefits people would be getting from that. It would have to be something that your individual PTOs can't provide, IMO. You might want to point out that any individual can join the PTA for a relatively nominal cost, if it is really important to them.
I believe that if you put a bunch of PTA and PTO people in a room together, you're going to find that they all have the same basic concerns for kids and ways of doing things. The day to day operations of a parent group within a school usually aren't too different between the two organizations. So, I'm sure that some people were very defensive about introducing the PTA because the implication is that the PTO is not doing enough, or not doing a good job at whatever they are doing, on their own.
Hope this helps provide some fodder for discussion for your group.