Aside from the sheer amount of energy and pollution required to put a factory into space, plus shipping all the raw materials, there are other considerations.
How ya getting the stuff back? It has to be in a vessel that will withstand thousands of degrees during reentry, and whose lifespan at best is very limited.
There will have to be industries on earth just to make the launch vehicles and fuel for them.
Speaking of fuel, a lot of nuclear reactors will have to be in orbit, because there is a limit to solar panels, batteries and hydrogen fuel cell capacity.
What are people on earth going to do for jobs once theirs are in space? Other than those making rocket parts and rocket fuel, of course.
How much are the space products going to cost once everything is factored in? Look what it cost, literally, to get a few pounds of rocks from the moon. Plus the amount of fuel to do it.
What's going to happen if one of these factories gets hit by an asteroid, and its debris in turn starts a chain reaction destroying other factories and satellites? There is already a huge problem with space junk floating around that could eventually cause serious damage to existing satellites.
The bottom line is, this is just another shallow touchy feely sound bite that sounds innovative, daring and green, but which in fact shows the idiot uttering it has no clue what he, she or it is talking about.