As regards Goff: he is not a bad QB. He is also a tough competitor and by all accounts a decent man. So I don't think whether one "likes" Goff or not that it has to do with his character. It has to do with his ability to be special or even to lead a team consistently to victory. At first, he seemed to be special and consistent. Ever since he got the big 2nd contract, at best he's not progressed. But most would say he's regressed (not horribly, but noticeably). With 6 years as a starter under his belt, at this point it's what you see is what you get.
As for Stafford, yes he'll make some head scratching throws sometimes. But, in perspective, he makes many times more good plays than bad. And the overall talent level from Goff to Stafford is significant. Further, Stafford is McVay's (and Snead's) type of QB. Amazing arm talent. Reads D's well. Feels the rush and moves well in the pocket. An amazingly tough guy mentally and physically. Doesn't implode when he makes a bad play or two.
As Cowherd pointed out; by year's end he'll have twice as many TDs as Goff. While that's not all on Goff, some of it is.
As an aside: I think Detroit will keep Goff and if they draft a QB it'll be using the Ram's 1st rounder (or even later) and not their own. And, that new QB will have at least 1 year and maybe more to sit and develop. Goff is plenty good for where the Lion's are in their rebuild.