There is zero evidence that Bones leg reach is any longer then Gustafs. If Bones is close enough to kick Gus, then hes close enough to get kicked.
Walk with me through this explanation since it appears you aren't getting what I am talking about (I'm probably not explaining my thoughts correctly). They are about a inch height difference, so their leg length should be close to even. So you are right that there is no reach advantage in terms of leg length, but just like with punches, the type of kick can also determine reach advantage. Just like Wandy's reach is no where near his actual arm length because he throws hooks instead of jabs, Jones has the reach advantage because his goal is to push rather than kick.
When Gus wants to kick JBJ he is going to have to step inside JBJ's reach to kick him because he wants to land with the side or front of his foot/shin. When JBJ wants to kick he will instead try to kick with the bottom of his foot putting him on the very outreach of Gus's kicking reach. Thus due to the goal of the kick it still leaves JBJ with a 2 or 3in to foot reach advantage.
My point is, even though Gus is the better striker, he still has a reach disadvantage no matter what that he is going to have to deal with. And he isn't fighting Struve who couldn't keep Barry from tagging him, he is fighting JBJ, arguable the best fighter in MMA right now and keeping distance rather than escaping to a safe distance (a la Machida).