But just because dirty water and sunlight produced cells doesn't mean that is the only way a cell can be produced, not to mention different types of dirty water.
Like I said before, they would have evovled to live in that kind of climate. Yes, bacteria is just a simple form of life without a conciense or a sense of self awareness, but it is life. Bacteria and complex species are both, reguardless of physical differences, forms of life. With that in mind, if a bacterial cell can live in an inferno, why does it seem impossible for a complex being to live in the same conditions?
Earth might seem inhabitibal to some other species because of how far away we are from our sun, they might think, "Geez, that planet is 20 degrees?! There's no way life could exist on something that cold".
There doesn't neccessarily have to be a limit for conditions that life can exist in, though I can understand why you, or anyone else, would prefer to think so. Not everything needs a limit, numbers and time are evidence enough for that statement.
This is getting interesting