The weirdest thing is the people accusing us of things we didn't do in the book, e.g. one guy said we claim there's no water on Mars. People keep saying we claim there's no solution to radiation when we have a whole section on shielding.
They're just not engaging in good faith. The older I get the more I realize most highly argumentative people don't actually argue. They just chuck straw men around.
Or people say we claim perchlorates are an unsolvable problem when we talk about one of the simple ways to cleanse them.
What we're saying is "there exists a solution" does not mean "the problem is solved." It's like telling your spouse the messy room isn't an issue because cleaning is an option.
That one in particular - folks seem to want to believe that radiation isn't an issue so no solution is needed. Propose a very real solution to the very real problem and they don't like you. Or, they want to believe that terraforming is the solution.