I think people need to be slowly convinced of somethings worth over time. To suggest there is anything useful to be gained for humanity cannot be supported and rationalized to the public.

What could be seen as more useful is industrializing zero gravity like space stations and slowly moving out towards Mars over time. To date I cannot work out any real usefully from the International Space Station.

Once someone dreams up some concrete advantage then humanity will go to Mars, remember we only got into space at all under 75 years ago ; so what is the hurry toward Mars : )

It is just space junk . . .

The only reason famous people do crazy stunts like promote Mars is the additional publicity normally equals the money they invest. None of these famous people are putting serious money into this they are promoting Mars simply to increase their business market shares on Earth.

If they had anything useful to spend their fortunes on on planet Earth such as poverty, disease, war, human trafficking or under ocean medical research we would hear nothing about a neighboring planet ; )