You mean players who knowingly and intentionally went into horrible matchups and got their ***** handed to them (something that could've happened against most of A tier), or players who went into fairly decent matchups and
got outplayed?
Peach has exactly 3 MUs that could be called counters. Two of those MUs are completely winnable, the other is Metaknight.
Metaknight is far too polarizing a character. He completely invalidates numerous characters who are either borderline or completely viable without him, including Toon Link, Peach, and even debatably King Dedede. And before Dedede himself as a polarizing force is brought up, Dedede invalidates exactly 1 character who otherwise would be (somewhat) viable, and that's Donkey Kong. Every other character which Dedede destroys has other equally or far more crippling MUs than Dedede.
That said I also support the banning of our infinites, so yeah.
As to answer your question, no, he didn't go into a horrible MU and get his *** handed to him. He went into a horrible MU,
nearly won, but lost because whereas MK can make plenty of mistakes and be fine, most other characters will get thoroughly ***** for the smallest of errors against the character. This is a character where most of the time your best option
still puts you in a bad position, a character who beats every character in the game except arguably one (Pikachu, I don't buy Falco or Diddy going even), a character with not one but
two broken and nearly unpunishable specials.
When you're playing a character who nearly everyone acknowledges gives a very large advantage, don't expect your match to be hype.