As opposed to Fifa and career mode, Konami has dropped too many features from the ML over the years instead of building on what they had. Simple things like Pre-season friendlies were removed. Why? Features that added replayability and depth like team popularity rating, player loyalty rating, balancing staff budget, upgrading facilities, real time development curves, pre-match tactical briefing, etc, etc, have all been removed and not replaced with anything better.
Add to that the broken transfer system (top players going to mid table teams), ludicrously low transfer fees, fatigue pretty much being a non factor, and the mode just doesn't have the depth or appeal (to me) that it used to.