Will Smith is a rookie, a 19 year-old one. It's only normal for him to have some difficulty in the NHL, playing for a team that just isn't good.
Some here are saying that it maybe would have been better for him to come a year later into the NHL, but my opinion about about the issue would be a little more complicated than that.
I mean, it is plain common sense that the best way to foster confidence/development in a talented young player is by letting that young player play at levels where he will build his confidence in his abilities and grow, giving him runway to speak of, instead of "throwing him to the wolves" in the NHL where every mistake of his is magnified and his confidence could get eroded over time.
But there is also a lot of experience that can only be gained by facing the very best in the world on a nightly basis. And it is important that prospects get that "reality check" early so they prepare well, and grow well.
The same thing happened with Slafkovsky in his D+1 and up until about the midway point of last season. He didn't score, and people got on his back about it despite the fact that his game was showing progression. Then he was put on a line with players that meshed well with him, and his progression took a giant leap.
So I get that some people would rather that Smith play in the AHL, or even had stayed one more year at Boston College, but I personally think that as long as Smith shows some amount of progress on a game-to-game basis, is insulated well in the locker room by veterans, and doesn't seem completely overwhelmed on the ice, that he should stay up in the NHL.
Now, if his confidence starts getting affected, and if Smith himself feels he might benefit from playing away from the San Jose Sharks in the NHL, then by all means, he should be sent to the AHL.
Those are the two options left for him at this point, since he signed that ELC.