I just taught two people to play Terraforming Mars IRL yesterday. Both are experienced board gamers. They quickly realized why the game allows you to take either one or two actions on your turn--without me explaining it to them. That said, they generally defaulted to playing two actions unless there was a compelling reason not to (many of those reasons have already been described in this thread).
If you go to his profile here on BGA, he has a link to his YouTube channel where he discusses Terraforming Mars strategy. He even has a video about how he became the top ranked player on BGA.
Part of the fun of board games for me is that people do play with a wide variety of strategies--and many games are designed so that those different strategies are at least reasonably competitive. Having to adjust/adapt to an opponent's strategy is part of what makes games interesting and fun, at least for me.
I went and replayed one of Threadpacifist's games. Granted, one game is not a representative sample. However, from that game I would say that it is false to assume that his games go fast because he always takes two actions. He regularly took one action and passed on the second--even in the first generation, when he could have played two right away. I couldn't even identify any reason why he would do this; he didn't seem to be trying to position himself for bonus. However, I am not nearly as good of a player as he is, so perhaps I missed something...As for your reference to Threadpacifist, are you certain that he ALWAYS takes two actions? Or takes two actions when there's no tactical advantage to playing one and skipping the second action (which is most of the time)?
If you go to his profile here on BGA, he has a link to his YouTube channel where he discusses Terraforming Mars strategy. He even has a video about how he became the top ranked player on BGA.
Part of the fun of board games for me is that people do play with a wide variety of strategies--and many games are designed so that those different strategies are at least reasonably competitive. Having to adjust/adapt to an opponent's strategy is part of what makes games interesting and fun, at least for me.