Ok, put it this way:
I think that there are many companies that deliver high quality material apart from Paizo.
So what is it that separates Paizo from the others?
What, in your opinion is it that Paizo is doing that no one else can match? What is it that Chaosium, Mongoose, Green Ronin, Fantasy Flight, Open Design and the rest of the very competent bunch of companies out there aren't doing?
Are you saying that only Paizo is giving people quality? That only Paizo is in tune with what their customers want?
Is quality the sole defining factor of Paizo's success?
That I don't believe for a second.
When did I say only Paizo is giving people quality... are you saying no one else publishing rpg's has any business acumen? And the only thing I was defining was why they, as opposed to WotC, are able to succesfully implement a model of mostly selling adventures and fluff books... not why they as a whole are a successful business.
However I do believe quality can entail many areas within a company and few have the total overall level of quality that Paizo has... As an example, I can't think of a single company you've listed that has the same quality of interaction with their fans and customer service. This is another facet of quality that I think greatly helps their success as a business. In the end I think them being a quality company has more to do with their success than a subscription model and being in the right place at the right time... especially over the longterm. That, for me at least, is why I support their company.