[pavel_lishin]

Sure, but then you're stuck setting up again elsewhere - so why not do it from the start?

Answer to rhetorical question: because we can't be bothered, so we'd rather just pick a provider who is more likely to stick around than not.

[spinchange]

That's a totally reasonable consideration but the revenue model of the host platform isn't always the best indicator of its success or longevity.

LiveJournal & Six Apart have longstanding revenue models but aren't hosting users like the President of the United States or large corporate media entities.

[pavel_lishin]

Sure, but they're still around. Or are you implying that the President and Corporation, Inc. would bail Tumblr out to keep their blog up?