Two basic principles in the income tax are:
1) things that are "consumption" are not tax deductible as business expenses;
2) compensation in kind is identical to compensation in currency.
Food is a classical case of consumption as distinguished from a business expense (chairs, work computers, etc). The theoretical basis is: you'd eat whether or not you were at work, but you wouldn't necessarily need office equipment if you weren't at work.
The effect of not taxing these beanies is regressive. The guy who works at Wal-Mart pays for his lunch with post-tax dollars, the guy who works at Google pays with pre-tax dollars.
Having a "company car" used to be a great perk, back when the tax code only considered it compensation if it was dollars.
We don't want to go back to those days. There was so much energy being put into working around the tax code and dead-weight from inefficient benefits. Even if you only got $4000 of value from the $8000 company car, it could have the rational choice given tax rates.
Are they also going to tax the chair you sit in? The computer you work on? The electricity to provide lighting and run the computers?