Ok maybe I'm just missing the sarcasm or something.
Considering the large amount of incorrect other statements they have made about how Action Surge works, I'm not sure it was hyperbole, but hell if I know what's going on
Basically, they thought Action Surge had a limitation it doesn't have, and feel that anything besides their reading of the ability is busted. Likely they're thinking "OMG, imagine doubling your attacks, that would destroy an encounter!".
Whether they're taking into account the massive hit point pools of high-level monsters, or the fact that this is not something you can do in every fight (just like how a Wizard can't throw out their big encounter-altering top level spells in every fight) is unclear.
They just think it's too much, while to the other posters on this thread, it's just a fact of life. Different paradigms, really. It's like how a few years ago, in a discussion about Sneak Attack, I had another poster claim that ranged Sneak Attacks could only be made within 30', limiting the benefit to the Rogue (I can only assume a holdover from earlier editions).
When I posted the exact text from the book proving that there is no additional limit on ranged Sneak Attacks over melee ones, they didn't seem pleased about it (I can't recall if the just dropped out of the conversation, ignored me, or gave me a "well, that's your ruling, then" comment).
Heck, arguments about Sneak Attack (and it's older brother, Backstab) are pretty common. I've had to dig out actual text quite a few times (I keep it handy these days just in case), because it's apparently one of those things that is subject to massive table variance. I've had people tell me that in 3.5 you can't Sneak Attack with a non-light weapon, and people tell me that AD&D Thieves were Backstabbing things left and right with a kill count that would put John Wick to shame- they have their paradigm, and they don't seem happy to have it upset.
The facts of the matter don't change the Mandela Effect of having something you thought you knew quite well be challenged.