2. Yes, definitely. Government should step in and run the show only when there's market failure.
If instead of something like capitalism we taxed people until they wouldn't have left over money to start new businesses, how would new businesses even be brought to life? How would you go about organizing group of people to work on a single goal that would not have immediate benefit and especially when a common lay person would think it's a complete waste of time? In such world where wealth was divided equally and 99% common people who don't understand the subject or potential gains many years down the line.
Would we use some sort of voting system in such a world on what we should build if that something would require 100B worth of resources to build?
I think if you managed to earn that 100B in the current system, it's evidence of your ability to use money wisely, to make something out of nothing, enough of it for it to provide more than 100B worth of value to the world, I think I would trust such person to make good decisions on next businesses and start ups as well as opposed to people collectively voting and trying to organize on what the next innovative attempt would be.
In the end worrying about him having 100B, just seems like envy out of ego rather than pragmatic thinking to me.
I don't think people are against space exploration.
When a dude alone can finance a space program it creates two moral issues:
1. How come a guy who make people pee in bottles have enough money for this?
2. Should space exploration be privatized this way.
Of course, you can see no evil here, but that's different from caricaturing legitimate arguments.