No QB, including Aaron Rogers and Tom Brady, have nothing but great games. They will have off days.
Further, often those off days are the result of poor field position because the D hasn't played well, or poor Oline play so the O has been made one-dimensional or the QB is under too much pressure, or WRs aren't getting open, or any number of other team performance related issues.
Jared Goff's numbers are impressive. He is moving steadily towards the upper echalon of NFL QBs. More than that he is a good leader, emotionally steady, consistent, and represents the Rams very well to the public. He is young, a hard worker, has displayed exceptional character, has great physical tools, and we see him do nothing but get better each year. And (and this is really important) he stays healthy and seem to avoid injury (this goes back to his college days as well).
Any thought that the Rams wouldn't resign him to a market level contract for an upper echalon QB is absurd. They have been preparing to do just that since he was drafted according to Demoff and Snead. They are both realists. They know QBs as good as Goff don't grow on trees. They also know that he is not likely to reach the level of a Tom Brady; but who else has? I see his potential on the Joe Montana level....... and I mean that in all sincerity. In fact, he's close right now. This coming year might be the year that we can make that as a reasonable comparison...... although to be an apples for apples he has to win a couple of Superbowls.