PDF is an open spec. Adobe's viewer sucking is a separate issue.
Do you know the whole story? PDF has not been created by users, but by a company.
Only now we have seen it changing into an ISO standard.
(Originally, Adobe only wanted to see it universally used to sell their PDF writers: please read for free, and please please pay for writing it. Only that it didn't happen this way.)
(In the sense of: you will never ever be able to desire all of our features we are continuously adding to our Take-Over-The-World-Document-Format?)
I'm confused.