The issue is that the owners proved their resolve to get linkage between HRR revenue and player costs. They have defended that linkage at EVERY opportunity, and the VAST majority of owners want it this way. Some fans, who either don't remember the pre-cap days or were a fan of the 6-8 teams which were able to take advantage of owner/market dynamics to have a VERY significant advantage, pine for the days where the playing field was completely skewed.
The goal of the cap in the CBA was to create the linkage - with "parity" being a distance 2nd. The owners aren't going to give up the linkage aspect to slightly improve parity when the no-tax state impact is almost certainly less than a 5% difference. That's a rounding error compared to other known and allowed issues in with the Cap.