Good post - have been meaning to have a look at server less stuff for a while. I'm not sure I trust Amazon not to raise the price later though, once they have a near-monopoly, and if they do, you'd be kind of stuck. It'd be nice to see a vendor-independent standard for this sort of thing.
It does seem haskellers spend more time pontificating about the purity and expressiveness of the language than building real projects with it. There is a downside to pure abstractions and brevity - it can lead to code which is so algebraic as to be inscrutable to almost everyone.