Re: "But the latest version is incompatible with the one you've got."
I can't agree enough with the "kludey mess" comment. SO many people that argue about software don't know the first thing about creating it.
I'll also add to the discussion that if the format has changed, then hopefully the company has innovated the software and made it better. That means they spent time and effort to improve it. In the real world, developers must get paid (I know I like my paycheque) so yes, new features should cost money.
Now if said seller of software is abusing the customers by forcing them to do things they don't want to do or add features they don't need, then it's up to us to create new software and sell it at a reasonable price. Thus the free market gets two great products and another small company gets a chance to make money.
If it were based on GPL, then Google/IBM/Canonical/RedHat would give it away for free, then start making changes to the API so quickly that everyone had to use *their project* and they become the de-facto standard. Nobody but the big guy makes anything in GPL.
Biting the hand that feeds IT
