If you could cook the same or better food at home for 10-15$ (which was my experience) them yes, employers are the reason for the extra spend.
You have the choice to bring lunch to work, so no, employers aren't the reason.
As far as quality if life is concerned, microwaved food doesn't quite have the same appeal for many.
Sandwiches exist. Of course, everyone is free to choose what they eat but the notion that there's no alternative to spending over $30 on food every working day sounds absurd to me.
There's always an alternative. One can also live under the bridge as a measure of saving rent (obviously exaggerating), but it's not a choice most people would make. The reason why we work is so we can support the lifestyle we want, not the bare minimum to survive.
You're missing the point - the time spent commuting is the real time-value lost here.