A playground for the rich

Once again, as the mayoral election draws near, the hand-wringing begins.  Rents in NYC are just too damn high.  Our current mayor has done very little to alleviate this issue.  The "housing lottery" system is a joke, and most units in the lottery are too costly for anyone making less than $60,000 per year.  The solution, for many people, is simple.  "If you can't afford NYC, just leave!"
Challenge accepted.
Let's set the bar for minimum income at $70,000 for a single earner.  On this salary, a basic apartment, transportation, food, clothing, and a few luxuries are attainable.  Anyone who can't meet that threshold has to find a cheaper city to live in.
Great plan.  New York is now a city without waiters.  There are no busing staff to clear your table, nor are there many cooks below the rank of head chef.  There are no housekeepers or custodians.  Certainly no store clerks.  That's going to put a damper on all the hotels, restaurants and stores so crucial to NYC's bustling tourism industry.  Continuing on to the performing arts scene, that would let out most theater staff and box office staff, as well as every performer and member of the crew of every show not on Broadway or at Lincoln Center.  So I guess nobody will want to see a show.
OK, so you don't really need restaurants, theaters or hotels.  And with online shopping, do we really need stores anymore?  Well, let's look at the things people actually need to survive in a city.  There are no new teachers, social workers, firefighters or police officers, and no EMTs period.  No traffic cops or 911 dispatchers.  No nurses below the rank of RN.  And that custodial shortage extends to the places we actually use, including hospitals and schools.  Speaking of schools, we've just gotten rid of all the para-educators who work with disabled students, as well as specialty instructors.  At the collegiate level, getting classes will be even harder because there are no adjunct professors anymore (as in the people who teach the bulk of college classes while scraping by on poverty-level wages).  There are no cabdrivers or maintenance workers.  And I hope that you weren't planning a remodel, because your contractor doesn't have a construction crew anymore.  Your nanny has also quit on you, as has your gardener and cleaning lady.  And if you hired a home health aide for your aging parent, that person has just left the city as well.
Going into the office, all of the financial industry will grind to a halt because the administrative staff has gone.  No receptionists.  No assistants scheduling meetings and drafting contracts.  No bookkeeping staff.  Sure, technology could handle most of it, but does a stockbroker handling billions in trade every week even have the time to manage his own calendar?
In our court system, there would be no legal aid attorneys.  No new hires in the district attorney's office either.  Clerks at every level of government would be gone, from the sanitation department to the DMV.  Gone would be paralegals and legal researchers.  And I hope you don't plan on spending the day in a city park, because the groundskeepers aren't there either.
You can't build a city solely for people of means.  It's the working people who not only keep the city running, but make it what it is.  They not only need a decent home, they deserve it.