Interesting. I read that in Jeff Goldblum's voice as well. Were there any missions that lifted off Mars and came back to Earth ?
But there are Mars rocks that have been busted loose from Mars, and orbited down to Earth.
https://en.wikipedia.org/wiki/Sabatier_reaction#Manufacturin...
I guess also wrapped into my statement was the thought that to be able to launch something back it would have to be landed very well and require some very complex machinery to prepare for launch, given the success rates of just being able to land something on Mars without it breaking. I went with the first reason off the top of my head :)
It's hard to justify the required R&D expenses without appealing to emotion (such as sending humans).