It is a cap issue primarily. Geekie is also the better player as of now. If Cooper and the staff don't see the need for him in the lineup at this time based on current team success and current line deployment, then there's no chance that Howard is disrupting that in games that could decide the division.
I don't think JBB really cares what other teams do or how they handle their prospects. Howard wasn't that great in the most important game of their season, that I do know. He has a great shot and has improved defensively, but he's still not someone the team wants on the 4th line.
He'll get a game at the end so he'll sign his contract, and then see if he can help the Crunch in the playoffs. If he doesn't like the situation, he can choose not to sign and take his chances with another year at MSU and then sign where he likes. I'm pretty sure the situation was made clear to him, both when he was drafted and after his college season ended, that playing time was not guaranteed but that Tampa would work with him, within reason, to get him signed.
He's good, but not so great he deserves any special treatment or considerations imo. If Tampa isn't playing for the division and the cap works, then sure, give him an extra game, but if they are still going for it, then as little time as possible should be given to a player with no experience at this level in games of that importance imo.