Jinder Mahal is an example of a guy who has been handed the most generic gimmick in all of WWE, and done nothing with it.
Remember what Stone Cold Steve Austin said on Tough Enough? You take chances or create your own windows for opportunity. They gave him the Ringmaster gimmick, and he did well with it, impressing WWE and earning him the chance to become the legend that he is today. Dolph Ziggler also went down this road. He was given rather bland lines to cut promos but he managed to show charisma and connect with the audience with it, and look where he is at now. He is in a feud with one of the top superstars in the company at the moment.
Jinder seems to be in the same situation, except he has done nothing with what he has been given. WWE is testing him with how efficiently he gets over using the "foreigner" character. So far he really has not garnered much of a following or reaction from the WWE universe. He does what almost everyone has done with this gimmick prior to proving themselves with it, cut a promo bashing American fans in another language. It's really to redundant and has been done plenty of times before in the past. Jinder failed to impress in his feud with Khali, as well as recently with Sheamus. In my opinion he has yet to have a match in WWE that been more than a squash or the casual TV match.
Thus why it leads us to the current situation WWE finds themselves in. They can not decide what to do with him due to his rather underwhelming first few months, so they have no direction to take him in. He hasn't given them a reason to give him a worthy and entertaining feud. It's like Amazing red in TNA, I loved the guy, but he didn't show that he could tell a story very well in the ring. You are right when you say that he has the WWE look to him, and has potential, he seems to be at least a decent in ring worker, and not afraid to talk on the mic (though his lack of fear doesn't make up for his shortcomings in terms of cutting a compelling promo). In terms of the title I would say that WWE will continue to sit on the pot until he looses all momentum and gets released, or he begins to show us some more than we we've gotten. His slow heel push may pay off in the end, but with his decreasing relevance in WWE I can't see him rebounding. Jobbing most of the time certainly is not going to help his status either.
WWE will get off the pot, they have pushed hard for the shit too come out but it didn't.