I like aggressiveness in hitters, so overall I don't like it. That being said, there are still times we have kids take pitches. Some HS kids it's ok to let them think a little at the plate, with some of them it's easier to tell them what to do.
When we talk "selectivity" in counts we mean to sit on your pitch or be picky, but nothing like a take sign.
Often with a pitcher with control issues and a weak bullpen, we'll let them be very selective 0-0 (meaning if it's in your super hot zone drive it). If it's a ball then it becomes automatic take till you get a strike.
A few years ago we could really swing it, so we hardly ever did any of that. Last year we were average to weak offensively, so it was a bit more common.
Taking pitches just depends on a ton of different factors.