We are a commune of inquiring, skeptical, politically centrist, capitalist, anglophile, traditionalist New England Yankee humans, humanoids, and animals with many interests beyond and above politics. Each of us has had a high-school education (or GED), but all had ADD so didn't pay attention very well, especially the dogs. Each one of us does "try my best to be just like I am," and none of us enjoys working for others, including for Maggie, from whom we receive neither a nickel nor a dime. Freedom from nags, cranks, government, do-gooders, control-freaks and idiots is all that we ask for.
The cost to the employer of hiring any employee, regardless of skills, is the training time required to accustom that person to the new company's methods and culture. This is a critical expense in smaller companies, which are the source of most innovation and new employment.
Some new employees should be paying the employer for the opportunity to learn the job, but that should be called "school", be it vocational or college level. Others work for no pay until they can assume sufficient responsibility to add to the productivity of the organization. That's called an internship. As weeks pass and by using cost accounting formulas, the owner easily determine the worth/value of new employee's contribution.
Mandatory pay scales are the death knell for small and/or new businesses.
Your sensible analysis assumes that a business exists to turn a profit. The people pushing minimum wage hikes think of a business as a black box that dispenses the goods and services they happen to want at a convenient price, plus pleasant jobs at a salary that will cover the nice place they'd like to live. If prices aren't high enough to pay the wages, the difference is supposed to come out of another black box labeled "profits," which in the view of someone who's never tried to run a business is infinitely large, and guarded by selfish people who don't want to share.