I'm pretty sure the parent posters were referring to large corporations whose core product is not technology as such, although even there, you'd be surprised (or maybe you wouldn't). You don't have to get far from MS/Apple/Google/FB/etc. to walk into an alternate universe of complete mediocrity, where engineering and development are viewed as cost centres and/or fancy forms of typing...
Even within those companies lurk a lot of mediocrity, either acquired or homegrown. MS and Google have had some stinkers over the years, apple seems better, but the probably keep the worst of it internal.
If you ever read stories about internal political wars at those places, you will realize they aren't so great to work there.
Specially taking into account the type of assemments being done to the employees, or which R&D unit is driving the main products (e.g. WinDev vs DevTools).
Yes, places like Microsoft System Research are great, but that is just a unit from the whole corporation. Same applies to the others.
