We just have a disagreement about the whole importance of statistics. I think they are fun to look at, you think they have real meaning.
Your argument is full of all kinds of opinions, as is mine, but ypu want me to accept your opinions as some sort of undeniable fact.
Example, you talk about "overall offense", what the heck is that ? You think OPS = overall offense, I think that's BS.
I feel that discussing who is the better player, offensively, defensively, or combination of both, is a purely subjective opinion, and no amount of statistics is going to change my opinion about that. There are way way way too many variables for any statistic to tell the whole story.
I prefer to consider statistics as part of an analysis, not as the whole analysis. Even more important IMO are things like MVP awards and World Series victories, after all that is the goal of the game.
Also, when considering statistics, I wouldn't say OPS is the most important. The two things that matter the most, offensively, are RBIs and on base percentage. OPS includes other stuff that isn't as important, so I wouldn't use it as a basis for who is the better player.
The only area where I see Piazza being superior is batting average, but that isn't a very important statistic for a clean-up hitter, RBIs is what a clean up hitter is supposed to produce; at least in the team game that existed in the era when Bench played.
And compare Piazza with his contemporaries and Bench with his.. when Bench hit 45 HR he led the league, when Piazza hit 40 it was good for a catcher, but it was not even close to leading the league.
3 times Bench led the league in RBIs, the most important offensive stat of all, and particularly for a slugger, has Piazza done it ever ?
When Bench was at his peak, he was arguably the best offensive player in the game, Piazza has never reached that point when compared to his contemporaries.
Piazza has better career stats in some areas, mostly BA, but career stats aren't necessarily more important than performance at one's peak. Both should be considered, particularly when peak performance leads to the ultimate stat, World Series Championships.