Flavor – How Is Microwave Popcorn Flavoured

A better instruction would be "do not rely entirely on the functionality of the popcorn button on your microwave, since microwaves vary widely as do bags of popcorn." But that's longer, and kind of complicated, so they abbreviate it "do not use popcorn button".

There's no problem with the power setting of the popcorn button, only with the timing. You should hang around near the microwave, and when you hear the pops slowing, stop it, no matter what your popcorn button thinks. And if you get a lot of unpopped kernels, and the popping didn't slow before the button said the microwave was done, consider doing it yourself next time and letting it pop for a little longer.

The problem with leaving it in too long is that the corn scorches (usually from the centre out) and the whole bag is inedible. If the energy is no longer going into popping kernels, it's going in to scorching what you already have. Get it out before that happens.

Popcorn kernels pop because moisture is trapped inside of a relatively gas-tight shell. As the kernels are heated, the water inside the kernel turns to steam. The shell of the kernel keeps the steam from expanding, so pressure builds up inside of the kernel until the whole things blows open.

If the kernel doesn't have enough moisture inside of it or if the shell of the kernel is permeable enough to allow the pressure inside the kernel to dissipate before it reaches the critical pop pressure, then that kernel won't pop. Ever.

So to answer your question, no. Take the popcorn off the heat before the popped kernels burn.