Disagreed. If anything, I'd say things that aren't possible to gauge with hard statistics, things like grit, determination, and "character" (as nebulous as that one is) are just as appreciated, particularly on this forum. Obviously I include myself in this, as evidenced by my admiration of Chiellini.
On the other hand, it seems to me, along with proponents of Marchisio as a starter, at least this week, that his main strength is that he "doesn't fuck up". After all, that's the gist of having supposedly great "decision making" and "positional sense". For the latter, I take it to be more so defensively, as certainly his positioning when going forward isn't spectacular.
So, in the end, you have a pretty good player, whose highlight is not making mistakes, rather than being "fast" or a "good passer" (to use your examples), or even being that exceptional going forward or safe at the back. Then there's his demeanour on the pitch which, as aptly as I can put it, is "quiet". I've never seen (or can't remember seeing) him fire up his teammates or take the game by the scruff of the neck on his own, as it were. So what's left? A player who isn't or cannot make a big demonstrable positive contribution in contrast to his peers at CM, but rather one who simply isn't making a negative one (via his avoidance of mistakes).
Other than that, clearly, I'd prefer it if we had a proper left winger (in the vein of Krasic) who does the job a winger should, rather than a jack of all trades who's supposedly providing "balance" in the face of our team having a bunch of handicapped left backs who add nothing defensively or going forward. Marchisio on the left is such a band aid solution that it irks me to watch. It beats buying proper personnel though, I suppose, leaving us with a one dimensional and somewhat predictable attack.