Water doesn't necessarily imply life. It means that there was a possibility of life, might I add life similar to that of Earth's. As far as we know, there could be various other substances that are able to sustain life. The only type of life that we know exists with water. There could be, and most likely are, other possibilities.
Pastlife said:
Any planet could have been inhabited. We have been here for a few thousand years. Do you know how old our universe is?
If a few thousand means around 200,000.
Hope said:
I don't think mars was ever inhabited. Just don't see how that could happen.
That's not an argument. It's merely an opinion, speaking from personal incredulity.