A couple of points. First, Mean Streak is not nearly as rough as the Texas Giant. Front seat to front seat comparisons with Beast are about equal.
Second, parks do not install trim brakes to take the fun out of the coaster. They install trim brakes to control ride dynamics for safe operation. Trim brakes add cost to the installation and and maintenance cost to the ride. So a park would not include them if they did not think them necessary. On the other side, the trim brake may ultimately save maintenance cost on track and train, by reducing stresses caused by excessive, yes excessive, speed. And it may really save cost in bad publicity and lawsuits.
My two points.