Running businesses with "lets offer more for free" and "ohh crap, they offer more for free, lets lower our price" is a race to the bottom.
It is actually moves like these that make me question Bitbucket more. How viable is the service long term? Do I want to trust all my own code to them?
It doesn't cost them a lot more in infrastructure to provide alternate dvcs - so your point seems to be completly invalid. More and more I'm starting to think that git is some kind of religion.
We benefit from competition between those 2 platforms and in the end this is what should count the most for us - customers.
One point, however, rings true: competition is good for we end-users, and it's certainly exciting that Bitbucket now offers both hg and git access.
To me it's opening to customers with different demands.
My opinion stems from running my own SaaS applications, seen the business downsides of all the free stuff, and now don't focus very much on the free aspect. I prefer trial.
I also recognize that me paying for a service I like is a healthy way to help that service stay around, because that is how I view it when my customers are paying me.
You are choosing to use Bitbucket for specific reasons. If they shut down because Atlassian is burning money and wants to trim the bottom line, then you now need to find something else to fill those specific needs again.
You don't lose any code, but you now need to figure something else out. And if you were relying on "free unlimited private repositories" you might not find that on another and now have to pay for something else.
Personally, I use GitHub daily for my job, but my private code isn't with GitHub.
On any available machine with some free space and an SSH daemon?
You talk about "figuring something else out" like it's some sort of big project. I don't understand that at all. There's no really effective lock-in here, users can take their repos and go anywhere or nowhere with negligible effort. They could even easily maintain a full copy of their repos on some backup machine at all times while using bitbucket or github.
And they can always increase the number of repos in each plan. I understand this won't make them as competitive on pricing, but the better user experience they offer has to be reflected in the cost.