As of posting this comment I just beat MMX4 on the X Legacy Collection (first time playing it again in probably over a decade), and boy I really wonder how people would have felt about the story had 90s era Capcom actually hired good voice actors. The guy who voiced Zero in Command Mission and X8 actually redubbed the Zero cutscenes in MMX4 some years ago and needless to say he does a much better job than whoever Capcom got back in 1997.

At least with Mega Man 8 you could argue since the story wasn't trying to be all that serious the silly voice acting kinda added to the charm (like Dr. Light's case of "Elmer Fudd Syndrome"), but MMX4 was trying to actually tell a serious story given one of the whole points of the X series is Capcom wanted to go a darker and more "mature" route (which was also continued in the Zero series).