I feel like some of the beat guys who break down film (like Lazar) noted throughout the year that his route running never really got better. Not that it was BAD, but it needs some cleaning up and Troy didn't seem to be making much difference there.
I sympathize with Troy, because it's not like the team has a long, rich history of drafting and developing wide receivers, so it's unfair to point to him specifically. And the offense has been such a mess the last couple years that he probably spent more time just making sure guys knew what the plays were, rather than teaching technique. But still, he hasn't done anything as a coach that stands out.