True, however most top players have her in their top 5, and their top 5s are typically out of order, so it's possible. She handles AM well and for those that she doesn't necessarily beat, she has her tools and can play her game for the most part, so if the player is solid, she would be an excellent top 3 choice to compete with any other character in top 3.
I think some players are just better at playing certain MUs than others. This also has to be taken into account when figuring out lists IMO because a MMH can be so good at playing against DDs because he plays DD himself, or has a sparring partner that was so legit that it honed the MMH's reads and knowledge of the MU so much that the MMH imposes his will at the start of the match and never lets the opponent get started. However (at least the last time I checked) DD is still not a favorable MU for MMH, just that the player tends to excel.