Not with that attitude!
I'm using fiction as an example of how this is a long-standing shared dream, not something ridiculous Musk just came up with on his own, as you implied. This is something we as a species have been looking at and working on for decades. It has been a long-term goal of every space program. People said landing on the moon was ridiculous or even impossible, but we did it. The only difference here is scale.
I reject your pessimism. That never accomplishes anything. Stop focusing on the hurdles and start looking at the ways we have to overcome them. There's nothing impossible about it, it's just an issue of resources, ingenuity, and willpower. We have proven that we can get spacecraft to Mars and land on the planet. We have proven that we can survive (and grow food) in a metal can floating in space, so we can survive in a metal can sitting on a planet. We have the capability to design the better craft and better metal cans needed to accomplish it, so where are you finding the ridiculousness?
His timeline may be too optimistic, but to make it happen, we only need to improve things we already have and use what we already know.
There's one thing I hesitate to ask. Was your opinion on the matter the same before Musk said he would do it? Did you give up a dream just because of who else shared it? People have.