Everything you're saying is true, but again I think it comes back to run plays vs pass plays. Right or wrong NFL officials are not calling holding on pass plays with any regularity and the vast majority of what has been called on the Cowboys has been in the run game or special teams. I'd have to go back through the data as it's a few weeks old now, but I know TJ Watt had 5 holding penalties called against him, only 1 was on a pass rush, the other 4 were in the run game. No idea if he's had more flags in his favor since or not. Micah Parsons is maybe the best pass rusher in football, but has been very middle of the pack in the run game. If my theory is true and refs are letting Olines get away with holding on passing plays around the league it starts to make some sense...again i'm not saying that it's the right thing to do, but from the NFLs perspective with so many elite athletes as EDGE players these days it would make for terrible TV as you'd have 10 flags thrown for holding every game easily and more QBs would be out with injuries. The Cowboys are an excellent team throwing the football, but have struggled all year in running it. From that perspective it starts to make more sense why the Cowboys offense would get more holding calls on them, especially with the constant shuffle they've played this year with so many players missing time and Steele getting a very slow start to the season coming off his injury.
Are the Cowboys getting screwed over? Yeah. Is it to the extent people are making it out to be? No. It is some big conspiracy against the team? I highly doubt it.