It's a slippery slope.

If a spear is Finesse (for the reasons you give, which I will not disagree with), then the estoc should also be Finesse. Which means that the greatsword (used properly, not just swung at someone's head) would qualify, as well as numerous spike-topped polearms, notably the pollaxe and halberd.

I don't disagree that the spear is poorly represented, but a line has been drawn by WoTC who developed the rules being used in this game. In a PnP game you can houserule to reflect your opinions and/or research, but in a CRPG the developers don't really have the option of variants for each play style.