Sages can put out fine DPS. I have parses on the top 50 lists too, but the issue isn't whether the best geared and skilled Sages in the game can put out good DPS. The issue is that if gear and skill are identical, a Sentinel will put out 8-10 percent more DPS in most fights. That's what the sims show and that is what the parses show.
Yeah maybe on a stand still, patchwerk style fight. But if you check simcraft for sages, especially hybrid and balance, they aren't massively effected by movement. If you implement "light" or "helter skelter" into simcraft, sages drop by 100-200 dps from simcrafted max.
The logs for Operator IX show that perfectly. The same melee players parsing 1800 for fights like dread guard are parsing 1300 for operator. Whereas i parse almost exactly the same on my sage.