Optimization does not mean that the game will yield high frames per second. If you look at what the game achieves, you could argue the game is quite well optimized, also for current hardware; the game is capable of utilizing multiple cores and multi-threading for instance. The TMTK does affect the loading times in a rather unpleasant way, making them a lot longer than they should be. The transitions between the scenery and building menus also seem to be affected by the TMTK. Note that this is likely a bug, which might or might not get fixed eventually (looking at the amount of broken features in the current game I wouldn't count on it).
For me, good optimization means it runs well on currently available HW so the game is playable and enjoyable. PC is playable for a while, then not. I guess some people just have different look at what optimization means. Anyway, if in early 90´s someone released game that has 3D graphics, but 3D accelerators wouldn´t be on the market, I wouldn´t consider the game optimized either. We have certain possibilities with current hardware and game should be designed to run effectively with that. PC doesn´t do that and as a customer, that´s what I rly care about. I would happily miss certain things from PC if it meant the game to be actually playable...
It would be at least nice, if it got better, but I must say it seems that currently PC runs worst it ever was and even beta played better for me.