Well, that's not exactly true. The year that JJ Watt won DPOY, Watt's season was considered one of the best seasons by a D-end in NFL history.
If you compare the two individual seasons, Quinn wasn't even close to being as dominant as Watt was the year he won DPOY.
And I have not heard anyone talk about Quinn the same way they talk about Watt. Quinn is good, but not even near as good as Watt.