Nope. This is decidedly untrue.
Dunn was actually a high BA (.304 career), plus hit tool prospect (270 K in nearly 1500 PAs) who got screwed up when an MLB coach insisted he swing for the fences more. Bruce, too, was considered a 60 hit tool prospect with patience and a fairly low K rate (21 - 24% K rate through his stint in the minors). He K'ed far more as major league coaches got ahold of him (and largely screwed up his swing too). Mesoraco was an extremely low K guy in the minors-- that was a primary part of his appeal.
The decision to focus on drafting loud tools with K issues has been fairly recent-- Dick Williams forward. (And, I'd argue, perhaps Dick Williams only.)
And, again, the argument is that it only takes one. If EDLC develops enough to be a legitimate All-Star, that's worth the series of draft picks and acquisitions in a macro sense.
All of them had pitch recognition in the minors and didn't need to develop it.