Here's some things against Jon:
Of course it can be debated but I try to stay objective when it comes to these things.
Silva beat his contemporaries (MMA wise). Jon came in when the old guard had already had their time. The legends of LHW had gone through rigorous battles by then. Great timing played a factor.
The other thing is the big names at LHW. This doesn't necessarily speak to the level of competition, but rather just that they were close in competition. Stylistic match ups allowed many different guys to attain the belt (but no one could hold on to it for that long). Thus bolstering their status (and the LHW division overall). When Jon fought the younger guys, he didn't look as good. These guys didn't have the name value of the previous legends that Jon fought but were still tough(er) competition, which speaks to my point.
I'm not saying that Jon wouldn't have been the best at LHW. I'm just saying that is part of why he was successful and why it looks better on paper.
Anyway, I'm not trying to win an argument or change your mind, just giving you some things to consider. I don't care who someone thinks is GOAT, I just want people to try to think deeper and objectively rather than just pick who they like best.