It's not a matter of taking life support for humans. It's a matter of taking life itself as we know it.

Most ideas on this involve dna-sequence libraries and machines to produce plants and animals from those, instead of actually hauling all the living things...

This is really the practical means of doing Mars and the Moon, not hauling all the stuff from Earth. So that puts those two projects into the 50-500 years category, not 10-20 years. So what.

Expensive beyond anything the greedy wealthy would ever give up.

More likely expensive beyond anything the greedy poor of socialist nations would want. They wouldn't want their monthly allotments of free stuff reduced to fund space missions.