Because you will be able to put away minor league hitters with pitches that won't work on ML hitters. You can probably afford to get a bit sloppy against minor league hitters up 0-2 or 1-2, most have probably already resigned themselves to failure that at bat.
Yea, they have dozens of fans watching their every move.
I've seen a few bits of Rays gear recently, oddly enough Devil Rays, but not as much as Lighting gear.