We've talked about the poor and inefficient development pipeline of Mexican players from Liga MX to Europe and the reason why. More Mexican players playing for clubs like Crystal Palace, Sassuolo, Freiburg etc., even it's not for the European heavyweights they'd still be playing in world class leagues, would be hugely beneficial
I also wonder if the Liga MX's format is counterproductive to the NT, i.e. an Apertura and Clausura which both have liguilla playoffs. On the positive side, it does have a refreshing amount of parity compared to the European leagues, as more teams have a realistic chance of winning a title. More teams have something to play for at the positive end of the table, as usually the battle for the last few liguilla places is very tight and exciting. A Queretaro or Toluca fan for example can realistically hope to see their team win a league title. However that format probably increases short-termism, puts more pressure on coaches who are more vulnerable to getting sacked after half a season, and gives less of an incentive to give young Mexican players vital minutes, than a long European style league season would do. Also that gives coaches themselves less of an opportunity to develop and grow in the job. You can also argue that it often rewards mediocrity.
That format though does generate a lot of money, more than one long league format would do without a doubt, and most likely increases TV ratings in both Mexico and the US. I believe that Liga MX games consistently generate higher TV ratings in the US on average (via Univision), than MLS, Premier League or La Liga games. I personally still find it a very fun league to watch.
Plus the Liga MX promotion / relegation system has been controversial to say the least, and does appear to stack the deck even more against newly promoted clubs. And I think there are talks (or have been talks) about scrapping promotion / relegation. And the bi-annual 'sudo-draft', where Liga MX owners meet at a hotel (in Cancun before the Apertura) to trade players between each other, is also highly controversial, and the players' foundation unsurprisingly want to get rid of it.
I don't think this is a massive factor on its own, but allied to the others it might be, and that is over the years I think that Mexico would have benefited from playing more of their friendlies away to good standard European teams (it doesn't have to be France or Spain all the time) in Europe, rather than seemingly playing the same cluster of teams over and over again in friendlies in the US. However I think they have a contractual arrange for that with Soccer United Marketing (SUM), and those friendlies generate a huge amount of money for everyone concerned. How many other teams in the world could pack in 90,000 fans for a friendly against New Zealand? As I said before, the Mexican NT are the probably the best and most passionately supported sporting team in the USA bar none.