I do understand the initial poster's POV here - he thinks there are better, younger players on the roster that are being held back by Ellis. Furthermore, trading Ellis could yield assets to help fill holes at another position of weakness on the roster - OL, NT, young WR...
However, it is uncertain whether the players he mentioned would represent an upgrade over Ellis. What is certain is that Ellis is playing well in his current role and has yet to be exposed as a converted DE - this may be due to scheme or due to him having better mobility than expected or a combination of the two. Until Ellis' potential weakness in coverage is exposed, he is providing a good pass rush and is forcing the run well to the outside.
I know some anticipate Ellis being a goner next year but he is still a productive pass rusher who has a reasonable contract so I doubt he is going anywhere unless we have a repeat performance of last offseason. So long as he is a starter at OLB and playing nickel snaps he will be content.