Kim Stanley Robinson has done his homework. He knows all about atompsheric partial pressures and soil ecology. He knows how to convey information via the written word competently. He knows not the first thing about people or fiction writing, though, and that's unfortunate. The Mars "trilogy" is a single boring, shapeless mass of words. The characters are laughably two-dimensional symbols, avatars for ideas or concepts -- they're not people. If they were, you wouldn't want to know them.
And they talk. They talk and talk and talk. They argue and argue. They talk about terraforming, they talk about politics, they talk about each other, in an endless cycle of debates, meetings, conventions, committees, assemblies, conclaves and arguments. Robinson has invented a kind of Model UN, he has worked to draw charts of manufactured political factions boring each other to death in interminable meetings. It is not interesting. It was not worthwhile to expend this effort towards such a boring end.
What is most depressing is not the boring storyline, the endless loops of the same argument, the stupid and contemptible behaviour of many of the characters, but Robinson's contempt for the English language. English, to him, is just a tool; a means of expressing information. If he could write fiction in equations he would. He ends sentences with "etc., etc." and tells us about his characters' lavatorial habits. He shows not a shred of joy, of affinity for his medium. There is no structure; "Red Mars", "Green Mars" and "Blue Mars" are all the same book. That this deathless, humorless prose is used to trace out a saga of such incomprehensible tedium is unforgiveable. Only the bland competence of the whole endeavor rescues it from complete failure; and even then Robinson has missed things: the SI unit of pressure is the Pascal, not the Bar, and that Kelvins don't come in degrees.