They did take the path of least resistance. Because as similar as the XB1 and PC architecture might be, the arcade architecture is even closer to that of the PC. The arcade version is basically running on a PC already. I do wish they had just ported the XB1 version over instead, though.
At any rate, I'm quite satisfied with the PC version. It's a noticeable improvement over my 360 version of DOA5 in both graphics and performance, so I'm gonna have to go ahead and disagree with you on your last point.