Holy jesus christ!! You got to be kidding me here. This is one of the dumbest ideas I have ever heard.
Dude people are being way too nice to you IMO, they should be grilling you so you don't get hurt. Go find the person who gave you this idea and commence to bitch-slap them repeatedly. Then slap them again.
If you are the person who thought of it, slap urself.
All joking aside bro, people have given their reasons, which all sound good. Putting anything under the skin is a horrible idea. In fact, when pinning gear that is the LAST thing you want to do, hence the long darts.
If u don't the idea of needle, remember this, there are tons more nerves on the skin than in the muscle. Sub-Q actually hurts more. I can testify, I have shot numerous compounds sub-Q and it sucks.