Pick a good one and sock it. Letting fat ones go by is just as poor from a plate discipline standpoint as swinging at bad ones. Unless you track whether the first pitch was a fat one or a bad one, I'm not sure how tracking this stat tells you anything without a ton of assumptions that may or may not be true.
I'll say this though, for a team that swings at a lot of first pitches, they sure strike out a lot. Seems like swinging at the first one and putting it in play would cut the strike outs down even if they just become weak grounders to second base. Also, the recent versions of the Reds seem to let more fat ones go by without swinging than teams I've watched in recent memory. I thought getting rid of Stubbs would help that (it has) but there are still a ton of guys who gawk at pitches they should be crushing. The single worst PA that I saw over the horrible Road trip was Xavier Paul striking out with guys on base while letting a hanging curve, belt high over the middle go by for Strike 2. He may as well have gone up there with a blindfold on.
Plate discipline isn't about taking pitches. It's about swinging at the right pitches. This team's problem isn't as much about the swinging or the taking, it's about the picking.