Wetware has life-support requirements. Even minimal wetware, though in spore form it may travel well. Depending on your definition of wetware, so long as you've got an ambient solar flux, power isn't hard to arrange, and it's possible that thermal sources (similar to existing deep-space power units) might work as well given what we've learned about deep sea vents and subterranean microbes.

Sentient wetware tends to bring along baggage of requesting rights and such, which can be expensive to provision.

Hardware can both survive and function in a wide range of extreme environments.