What do you recommend doing for unskilled people working for such low pay?
If you just keep raising the minimum wage, they will not have any reason to
learn a skill.

A recommendation based on experience:

When I ran businesses where I had a lot of employees, (well sort of "a lot"-
had about 65 once), there were always a few entry level jobs that paid minimum
wage. I guaranteed my commission sales people minimum wage, but they also
understood I guaranteed they'd be putting their desk in a cardboard box if they
didn't nearly always exceed mini-wage by a substantial amount.

A business organization thrives as it brings its people up, not as it holds
them down.
The kid that hires on as a mini-wage lot boy shuffling cars around and picking
up trash will hopefully prove to be a good employee that you train to become a
higher-wage detailer or lube rack technician. If not, you dismiss him and
replace him with somebody that can help the organization grow. No reasonable
business person wants an employee who is so marginally productive that it makes
no sense to pay more than $7.15 (current mniwage in our state) per hour.

When a guy says, "I can't afford to pay my help more than $7.15 an hour", he's
really stating, (IMO) that he's a lousy manager and unable to motivate his
people to be productive. Business is all about getting rich, but in its best
form it is also about enriching others along the way.

The guy who thinks he's got the world dicked because his $7 an hour employees
produce $30 an hour gross profit is usually lucky to rise above lower middle
class himself. Give me a $15-25 an hour guy who can produce $100 an hour any
day over a miniwager who can barely justify his nothing salary. I'll take as
many hundred dollar bills (that I can buy for $25@) as I can get, and thank you
very much. :-)