So here's the question I think you need to ask yourself and sort of what ISBPathfinder was getting at (I think): Is lock out/extreme stax welcome in your league at all? Because if the strategy is a) competitively viable and b) operating within all the other parameters of the league, I think you should leave it be. It's not really much different than wiping a table with a combo, except the onus of the losses is on the players who choose (prematurely or otherwise) to consider themselves beaten.
Either way, I don't think punishing the competent player is the correct situation in an admittedly competitive, prizepool-oriented environment like a league.
Either way, I don't think punishing the competent player is the correct situation in an admittedly competitive, prizepool-oriented environment like a league.