Bottom feeders are the ones whose agents are licking their chopsIt does the opposite. Most teams will have a 10m+ player soon. You create a hard franchise tag number. Say $12m. If Toronto signs Matthews to $15m they can franchise tag him and only $3 mil would count against the cap.
Meanwhile other middle of the row teams can use the exemption for their top players and have room to add at deadline is they're having a good year. There are surprise teams every year.
The bottom feeders are irrelevant. I don't believe in catering to the lowest common denominator. Most teams are average and this system helps them as well. The NHLPA would obviously agree to it.
Now your getting a 70 point player on a shit team getting tagged when the agent says " hey its free cap money "
Next man up and player comparables creates issues