The numbers aren't as drastic as articles like that make you believe. For example you apparently pay tax for everywhere you play. So only half your games are in Tampa for Stamkos for example. Then there's also to take into account how signing bonuses work. How do they get taxed? Based on where you live? If you live in a state with no state tax can the team work around their bad taxes by paying out a contract in signing bonuses and still get the "cap bump" in their favour? Then there's everything people do to get around taxes, that can't as easily be quantified the same across the board.
I wouldn't hate a cap system where teams do get cap bumps based on tax but it wouldn't be as simple or as drastic as the writer of that article did, obviously that was just an example.
They'd need to work in the game location breakdown to figure out how much tax affects things(it's not as drastic as people pretend it is), then if the signing bonuses tax differently they'd have to take that into account too, so if a team uses them to get a player for less they lose from their "cap bump" whatever percentage of cap they gained by using signing bonuses.
I would like something like that to be incorporated but I'm not sure the league wants to get that complicated with the cap.
Also to add to the conversation earlier. Yes all contracts are paid out in USD so with a 15% exchange rate, and someone exchanging to Canadian Dollars a 1 million dollar contract gets them 1.15 million Canadian. However this money is just as valuable as 1 million USD. Often times you're paying more Canadian for the same commodity in USD. You're not gaining much if anything at all, and sometimes you may be losing.
Often times people make it seem like, because they're both called "Dollars" it seems like you're getting more money. If I got 1 million dollars and went and exchanged it for 107.24 million Japanese Yen I wouldn't be getting so much more money. I'd have more units of that currency but not more value. When buying thing with Yen I'm paying a lot more Yen than Dollars.