I think the biggest issue with ramming is that it basically just doesn't pay off.
What the Soviets, Germans, and Japanese all learned (thought the Japanese ignored it) was that the crew training/attrition wasn't being factored in, and it was killing them.
Pilots (and starship crews) are murderously expensive to train, and it takes long periods of time. You DONT want to send your best pilots or crews on ramming attacks, because they are more than likely going to get lost in so doing. So, you send the raw barely trained newest recruits, and the down side is that they can barely operate their craft, much less pulling off the fairly difficult stunt of hitting a very fast object doing its level best to AVOID being hit.
Long term, it empties out your manpower pool, and you don't have replacements to the veteran crews to keep them functioning efficiently.
In the case of Japan, they had some absolutely excellent planes by the late war period (Ki-84 Hayate, N1K2 Shinden Kai) but not enough experienced pilots to fly them.
From an Aurora perspective, its a hellacious waste of resources, if you think missile combat is an economic drain, ramships are even worse.
So, huge economic drain + huge manpower drain = Fail.
And also from a game perspective, it would more than likely get abused to hell and back, and I thinks thats one of the reasons Steve didn't allow PC ramming.