Adam Wainwright - Lifetime AVG-.223 OBP-.254 SLG-.333 OPS-.586 That's atrocious.
Jason Marquis - Lifetime Avg-0.197 OBP-.326 SLG-.283 OPS-.499 Beyond atrocious
He actually had one maybe two good hitting years in STL, he's blown before and ever since.
Jeff Suppan - Lifetime Avg-0.174 OBP-0.221 SLG-0.238 OBS-0.465 So beyond atrocious you can't even see the line for atrocious.
As for the rest of your post, you can't compare the game now to the game then. It's completely different. I hate to say but, Ozzie Smith would be an average Shortstop value wise in today's game. Just look at his stats. Defense is overvalued past a certain point. Making unbelievable plays is great and all but they are rare to happen and 0 for 4 days at the plate are much too common. The rise of sabermetrics have helped show a player's true value. If Mike Piazza was such a liability like you said, then why did teams pay him so much money to play for them and crush bombs? Jose Canseco played outfield most of his career, not DH.
From the first random article I found on the subject:
Don't be misled, though. In modern-day baseball, being the "best-hitting pitcher" is like being the world's fastest snail. Last year's stat line for the Cubs staff: a combined .201 batting average, .220 on-base percentage, and .302 slugging percentage. These are the numbers that give the Cubs such an advantage over the competition?
As the game gets tougher, the pool of two-way players dwindles. In Little League, the best player usually pitches and plays shortstop. The same is true, to a lesser extent, in high school, where raw athletic skill is more likely to prevail over specific, learned abilities: The cleanup hitter might not only be the pitcher, but also the point guard and the starting quarterback. A few collegiate stars—Dave Winfield, Mark Kotsay, John Olerud, and Mark McGwire, for instance—star on the mound and at the plate each year. But when pro teams get their hands on a rare pitcher-hitter combo, they usually make him focus on the batter's box.
