I think that's a part of it. I'm a biochemist and because of what I've learned, it's very hard to imagine things any other way. DNA and proteins and all that just flies apart at temperatures we can find around us, let alone at 1000° or more. Our whole existence falls within a narrow range of energy and mass densities. There could be other solutions and it'll be hard for us to find them.Of course, this can be explained away by the antrhopic principle: life exists in such a narrow range only because we exist here in that range to ask the question.
But everywhere on this planet we have enough time to look carefully, we find life. I think that will extend to any environment we are capable of exploring. Energy gradients are widespread, and anywhere you can extract energy by running a chemical reaction downhill, something will evolve to do that.