Although the situations are obviously different, the uproar reminds me of when I started charging for HomeSite. You see, the first version of HomeSite was free, but after months of providing free software - and free support - I decided I needed to start charging for it. It was impossible to handle my full-time job and work on HomeSite, so I had to give up one of them. My day job paid well, but it wasn't much fun - so the choice was obvious.
Now, I announced that I'd be charging for the second version of HomeSite several months in advance, so I was completely unprepared for the uproar once the price went into place. Messages similar to this Usenet post hit my inbox, and my support forums were peppered with personal attacks.
Having been where the Six Apart crew are now, can I make a suggestion to those who are flaming them? Even if you live in some bizarro universe that equates earning a living with belonging to a satanic cult, if you're really not willing to pay for MovableType, at least have the courtesy to thank them for the free ride up to this point.