For starters, the player has to agree to it too. When a recruit signs a scholarship agreement with a Big 10 school that scholarship is guaranteed for four years. If the coaching staff doesn't think they will get much playing time and want to open up a scholarship they can tell the player "you aren't going to get playing time here so we suggest you transfer." This is enough for most players, because most want to play, but what if the player doesn't care about playing time? Gas was still learning the game of basketball, and might have realized that he wouldn't have a ton of other options. Maybe he didn't care about playing time and getting his degree from a high quality institution was important to him and his family. It's very possible (if not likely) that Gas was made aware that he wasn't going to play much and was encouraged to transfer, but decided he didn't want to do that.
And I would have no problem with this. It's not a knock on anyone. The coaching staff is doing their job when they try to turn over the roster in ways that help the team. But it's a four year agreement in the Big 10, and if the player doesn't want to leave and is okay not getting much playing time then he should stay where he is comfortable.
I think it is viewed negatively in many cases, but it doesn't have to be. I think we ran Matz off to make room for Crandall. The timing was just too perfect. That doesn't mean it was some ugly backroom deal. My guess is Pitino brought Stockman in and said something like: "Matz, you've been working really hard for us and we appreciate it. We want to do right by you and hope you want to do right by us. You are going to be finishing up your degree here soon, and we just don't think this is going to be the right fit going forward. We have a chance to bring in a guy who can really help us, and we'd like you to grad transfer somewhere else so that we have a scholarship for this guy. We'll give you a good recommendation to any school you want to go to, and I bet there are some really good programs that will have a bigger role for you than we can offer. So what do you think?"