The problem with Earth isn't Earth, it's us. Going to Mars isn't going to change everything about humans that has made us hellbent on destroying ourselves. It'll definitely be cool and exciting, and sure, maybe it'll offer some protection against a once-every-billion-years asteroid, but that is not the threat we face today. The threat we face today is ourselves. Going to another planet isn't going to fix that; it's just going to move the problem to a new place. At this stage in our development, thinking that colonizing Mars is going to solve our problems is like someone who has had a string of bad relationships thinking that maybe the next one will magically work out despite having taken absolutely no stock of themselves.
I think your analogy is not valid. Colonizing Mars is like having another home in different country in case that current home is destroyed by fire. It has nothing to do with relationships, apart from being able to have relationships at both places. Sometimes changing your neighbourhood actually helps.
I see what you're saying but I disagree because I think your analogy inverts the risk analysis. In your second home analogy, a house burning down is an asteroid. But the chances of an asteroid hitting Earth in any reasonable timeframe are so minuscule as to be completely negligible. Far more likely is that we destroy our own house through willful negligence. Having a second home doesn't mitigate that risk in the slightest. It just means we burn down two houses instead of one.
I agree with your risk analysis. Destroying civiliasation by ourselves is much more likely, it even happened several times, humanity still survived, but now we have weapons which can fuck up whole planet much more thoroughly.
BUT we can still insure against more than one scenario. Having home on another planet seems easier than changing whole humanity so we should at least try.
The problem with Earth isn't Earth, it's us. Going to Mars isn't going to change everything about humans that has made us hellbent on destroying ourselves. It'll definitely be cool and exciting, and sure, maybe it'll offer some protection against a once-every-billion-years asteroid, but that is not the threat we face today. The threat we face today is ourselves. Going to another planet isn't going to fix that; it's just going to move the problem to a new place. At this stage in our development, thinking that colonizing Mars is going to solve our problems is like someone who has had a string of bad relationships thinking that maybe the next one will magically work out despite having taken absolutely no stock of themselves.