Me sitting in a corner and drinking is doing something. Me burning down my house is doing something. Neither actions are productive.
Is Elon doing something productive? With cheap rockets, arguably yes. With colonizing Mars... it's less clear.
> The technology that SpaceX develops can and will be used for much more than just Elon's particular vision of Mars colony.
Like what?
> Oh, why Mars, why not Moon, or Ceres, or O'Neill cylinders, or lets colonize the Sahara desert first, or lets solve world hunger and poverty (which is a 100% political problem, not technological, BTW)
It's hard to solve political problems, because everyone knows how bad people can be. It's easy to dream about solving engineering problems. People have been doing it for millenia. We just build a bigger / better / faster / cooler thing than what we have right now! See? It's easy!
I find it instructive that most of the "pro" arguments are based on dreams and hope. Most of the "con" arguments are "Have you seen how freaking difficult it is?"
Dreams won't feed you in the cold, dark, airless, nights on Mars.