The problem is how much money do they have to sink into the team that even gives a strong probability that they'll win another round, or two, or three? And how much revenue (net) can they expect for winning each round?
Put it this way: If MLSE decided today that their *only* priority is winning the Cup and they'll spend whatever it takes, even if it means a loss financially, what moves could they make that would even come close to ensuring it? None. Even if every single executive, GM and coach were available and the team brought in the very best of each, remember all but one of each didn't win a Cup last year.
(Add to that the roster, with these latest contract extensions and something like 17 roster players with some form of NTC/NMC)
Point being, it's fairly easy with the resources this franchise has to put together a solid, winning (as in consistently making the playoffs) team, but it's another thing entirely to build a championship team. No amount of money guarantees that in the salary cap era.