You have to realize, if you are suddenly put in a new place where you dont understand the meta and everyone is soooo much worse than you, its hard to give good advice.
M2k gets to play somebody in like 1 or 2 matches, thats no where near enough time to fully analyze and learn a player to the point where you can give them a good idea of what areas they really need to work on and how.
I see a lot of bad players give other bad players advice that they just sorta regurgitate and then think giving advice is easy, its actually quite hard in such a short time to give really useful advice that is exactly what that player needs to hear, and a few people got advice from m2k and then didn't understand it because they didn't understand the game enough to understand what he was trying to tell them.
Once you can think about a game on a really deep level it can be very hard to go back and think on a very basic level, most likely m2k didnt understand why players couldn't grip the most basic parts of the game and would have had no idea how to tell you to understand those basics.
The biggest thing of all though, is people expecting that a top level player can come down and you can learn heaps from them in such a short time or a few matches.
In order to get better you'd have to play a player for many hours across a few days, one short session with a few matches isnt going to teach you much if anything, and so expecting to just suddenly improve from that is both shortsighted and unfair to the international. Whilst voting keep this in mind and also keep in mind that smash 4 is still being developed and explored so its harder to put you on the right track for improvement because the tracks are still being made (whereas this isnt really the case in melee)
Finally, expecting to just get better from top level players doesnt really work if you are too far behind them, the idea has always been that the better the player you play and the more he kicks your ass the better you'll get from player him, but there is a limit.
You'll improve a lot more if the person beating you isnt too far ahead of you, that way you'll be able to grasp why you are losing, but if they are light years ahead of you you'll just get ****ed and really have no idea whats going on.
P.S also there is no shortcut to getting better, if you think playing a top player is a 'get good quick' device, and especially if you feel entitled to some advice after playing them, then you dont have the right attitude.