For the vast majority of baseball history pitchers, at least starters, were judged on ERA, Ks and how many wins and losses they had.
Yeah, and they used to throw complete games. With so few pitchers going the distance these days, it's becoming more and more of an archaic statistic. At best, a pitcher used t have 50% responsibility for a win or loss, if you think defense has no impact. But now, with pitchers rarely going to distance, at BEST, they have about a 33% impact, which is how long they pitch for.
Wins don't matter for pitchers today because they aren't on the mound when the game is decided. Well, then there's the fact they can't score runs, but you get my meaning. I'd rather discard how wins are calculated, and look at a team's win-loss record in a pitcher's start regardless which pitcher gets assigned the win.