You've forgotten about all the times when the traffic signals on the frontage roads used to back cars up onto the freeway, causing traffic on the freeway to go less than 10 MPH for 4+ hours at a time. University, Briarcrest, Southwest, and even SH-21 used to have this problem, multiple times per month. It meant that any malfunction with any of the frontage road signals would cause gridlock on the main lanes.
The new ramps are NOT a logistical or physical problem, they're a driver behavior problem. If people would use them correctly, they are superior to the old ramps because they ensure proper queue lengths for the frontage road signals even in the event of a malfunction. Once drivers learn that they need to accelerate to merging speed (USE THE PEDAL ON THE RIGHT!), everyone's going to see how much better they are.