Yes, lets retard human technological expansion to answer a fairly irrelevant question in the grand scheme of things, that seems prudent... While I think going down the gravity well on mars is stupid, it's stupid because there's no need to trap people there when we should be able to more closely approximate earth gravity and generate nearly limitless surface area while having access to more useful minerals with o'neill cylinders (or something along those lines). Ironically, this could go a long way to fixing the earth...
Also, it's really boring whether mars has/had bacterial life or not. If it does, then it rejigs the math on everywhere else, making it way more probable we find it elsewhere as well. That leaves us with it's either not there, so it doesn't matter, or it is there and it's probably in a lot of other spots too, so we'll find it on the next one, once we're actually established in space and multi planetary and the cost of not going to said next one isn't as high as holding the whole species up from getting off this rock into space permanently. The only situation where it actually matters is the very slim chance it's both there and deadly to humans in a way that makes it likely the astronauts make it back to earth and contaminate us all before it kills them.