In spite of the drug use, Dallas was the winningest team in the NFL, from 1970-1990.
So, the "drug use" obviously didn't affect the team.
If anything, Dallas showed patience with people like Harvey Martin, who would have been canned had he been working for IBM.
But, when player after player turn out to be dealing drugs, assaulting women, etc., then it reflects on the team (or should at least).
And, if you're referring the the Landry or Johnson-era Cowboys here, you're flat-out wrong.
Barry Switzer, Johnson's successor, tolerated Michael Irvin's and Nate Newton's and other players' off-field antics, just as he had with the Oklahoma Sooners, yet still went to the playoffs and Super Bowl with them.
You've got a grudge against Dallas, and single them out, when there were as many or more druggies, and wife-beaters and malcontents on other teams.
They didn't win, though, so who the hell cares, right?
And do you really think that Irvin et al were model citizens under Johnson then all of a sudden went beserk under Switzer? Get real! Also, there were as many criminals on the team under Landry as during any other era. But I guess winning division titles and choking in the playoffs excused all of that! And name another team that has consistently had as many players, over the decades, in trouble with the law as the Cowboys. Even the Raiders look fairly tame in comparison.