The point is that real NFL players don't react differently just because it's fantasy football playoffs. So there's no legit reason to care what his career stats are in weeks 14, 15, or 16 and more than you'd care about weeks 3, 6, and 11.
Being right more often than not? I don't know your track record or history, and frankly I don't care. You want to be over-the-top about calling him droppable, go ahead. He was WR22 in PPR between weeks 6 and 14 despite catching only 2 TDs passes. How many leagues do you play in that start only 1 WR? Sucks that he laid an egg against the Steelers, but that's not too shabby for joining the Patriots a couple weeks before that.
Nothing this year really mattered before week 6. I agree that if you don't want to factor in not being used in Cleveland, being traded midseason, and then taking a few weeks to adjust to a new team, sure his 2018 was a massive disappointment. If you want to be more realistic about what he did this year, well, that paints a very different story and one that doesn't fit your narrative very well.
Gordon's value is higher now than it was at the beginning of the year. Why? Because for the 2nd straight year he stayed clean, and for an 8 week stretch after getting acclimated to a new offense midseason, he put up low end WR2 numbers with only 2 TDs. If he can do that without any offseason or any pre-existing chemistry with a QB or knowledge of a playbook, that's the FLOOR for a healthy and sober Josh Gordon.