The least skilled to play? Marth. Your disjointed hitbox gives you the advantage in battle, allowing you to repeat the same move(fsmash...with a lil tapjump)...over and over again, maybe a counter if opponent gets too close, and finish with a nice spike. DONE! Why so many like marth? Now you know why
OMG, that is by far the most horrible Marth strategy I have EVER seen.
F-smash, dair, COUNTER? Those are all among marth's worse moves, I can't even remember the last time I used counter (oh, yeah, I can, gimped an Ike), and the others I use sparingly because bair and fair are much safer edguards then dair, and f-smash is EXTREMELY unsafe, and it's not even that fast (10 frames). Counter is even more unsafe, and requires you to predict your opponent exactly when there are plenty of options that require less exact prediction and are more powerful, it's only useful against moves with REALLY laggy start-ups.
Marth is about spacing and zoning with fair and nair, using the same to apply shield pressure, spaced dtilts, and punishing with (mainly) dancing blade, or otherwise dolphin slash, f-smash, up-smash, etc depending on the situation. But generally Dancing blade. Also grab games.
It sounds easy, but it's very reliant on spacing, moreso then any other character except in specific match-ups, because a few pixels is the difference between move safety and getting punished. You also need to know instinctively what your safe punishing options are.
1. Any Marth that plays like the one you described should die immediately against any player of any character with any skill whatsoever (yes, even a Ganondorf player).
2. Judging a character's difficulty level by the habits of individual players is stupid.
3. Generalizing an individual's habits to the habits of every person who plays that character is even more stupid.
The fact that you happen to be judging it off some of the worst Marth players on the planet just proves this, watch one of NEO's matches, heck even watching some of mine would show how wrong you are about Marth.
Moral of the story: Learn at least a little about the character before shooting your mouth off.