None of these cities have any incentive nor interest for NHL.
As a business, if any of these cities was worth spending half a billion on a hockey team, it would have been done ages ago.
If the NHL isn't interested in franchises being in Seattle, Houston, Hamilton/Toronto, Quebec City, etc. well....there is something wrong with the league then.
Only in the NHL can someone that follows the league (apparently, I assume you do powerstuck) would claim that franchise locations that would be a huge boost to the league revenues and exposure be of no incentive or interest to the league.
As a business, those markets should immediately get franchises at an enormous discounted rate....I'd even argue giving them franchises for free would be a smart business move.
That's IF....huge IF....the NHL wants to operate like a business and grow revenue.
The problem is, they don't. If they added 4 teams quickly that were immediately successful and huge money-makers (QC, Hamilton/Toronto, Seattle & Houston) that would rocket the cap up. Teams like the Panthers, Hurricanes and Coyotes would wind up in serious financial problems with salary cap (read: floor) increases.
So...it would also lower the profit of other teams. If you're the Rangers, Habs or Leafs and you're raking in $60-80M a year in profits.....why would you want league revenues to increase? That would increase the salary cap and and now you might only be making $55-75M a year.
The big NHL teams don't want the league to thrive.....the tiny NHL teams don't want the league to thrive......if anyone aside from the players wanted the league to thrive, as you said.....it would have been done ages ago.
This is why the NHLPA wants a say in relocation/expansion....because they KNOW the NHL isn't interested in quickly increasing their revenue.