For Google, if this is still a 'risky venture' then they are simply in the wrong business, they have the scale and should be able to offer their infrastructure at a cost that is quite profitable. There is plenty wrong with Amazon but they have never ever given off signals that they might withdraw their infrastructure offerings from the market. Microsoft also hasn't but then again, they do have a history of launching stuff and withdrawing it again (Xbox the notable exception, that took forever to take off and they stuck with it). Google has taken products off the market not because they weren't profitable but because they weren't profitable
enough. That's the nightmare of early infrastructure adopters who will - by that time - be bound hand and feet.
If you're in competition with the likes of Amazon and Microsoft and you intend to go after the same customer profiles then you would do well to ensure that your messaging is what those customers expect and that every outward signal you give is that you're in it for the long haul, with a much longer horizon than the companies that are going to be your customers can oversee so that the trust becomes implicit.
That way if some internal document gets released it doesn't look as though you are still undecided.
Anyway, no need to take my word for this, let's just see how it plays out in the longer term.