Many shows emulate others... but this seems to just have nothing original to it.
Primarily it feels like Buffy.. a normal person, having a special role forced upon them. History, mystery, intrigue. Yawn. I loved Buffy... but Buffy is from the '90s. Even the effects on some of the monsters in Grimm was like something from Buffy.
Its other key influence is of course Supernatural... another show that I love, but don't necessarily want to see copied.
So the parents are dead... mystery. Yawn, seen it before. The mix of dark topics with light humour/dialog. Seen it all before. The supposedly 'clever' things like 'R H' on thie child's satchel - yes, we saw it... too obvious. The bad guy humming the music... did you see it viewers...did you see it? Of course you did, too obvious.
Wooden dialogue. No spark. Uninteresting cast. Nothing. It felt just like a mash of loads of other great shows that we've already seen.