I wouldn't even come close to saying it is cheap. As you point out, he has a 2 way contract, but on top of that he was given a guaranteed minimum by the club. That references the fact that both parties discussed this possibility at length. Beyond that, he hasn't proven that he is better than anybody in the lineup, even Marty.
As for the reputation, I really don't see how this hurts the Avs in the least. They negotiated 2 year deal with a minimum salary. They were upfront and honest with Gabriel. Any player in a similar situation will get the same run down.
It doesn't hurt them a great deal. Only potentially, and only with a smaller signing. It potentially may be something that an agent looks at when advising his client where his best options are to sign. They'll say, you could sign here in Colorado, but keep in mind they sent down Gabriel Bourque last year just to save money. Gabriel Bourque isn't Ben Smith, he's an actual NHler. If they did that to him they might do it to you. It'll be up to the player whether they want to chance it or take a PTO or two way deal with another team.
I'm not sure he has a guaranteed minimum either. Where did you see that? CF could be wrong, but they don't have that listed for him. They do for Stanton and O'Brien but not Bourque. Just his $200k AHL salary.
It's just a little cheap (not in the financial sense) to me because like I said Bourque is a proven NHLer. He hasn't played poorly either, it's just that Marty has played well. Marty took a step back last game too, and another off game next time, and Bourque should have be the next guy called. What happens if he gets hurt in the minors? Then he's really screwed.
Again, not a huge deal, just doesn't totally sit right with me given the player. He knew it was a risk when he signed the two way deal though. He probably just thought it would only happen if he played poorly. Not everything is fair in life though.