Flunked Economics 101, eh?
Any job which can potentially be performed by robots will eventually be performed by robots.
Offsetting the initial investment, robots do not go on "strike" (think Cesar Chavez), take days off, require medical benefits, family leave, workers' compensation, salary, raises, sick days, etc. They don't vote Democratic, either.
There are already commercial robots which can clean toilets.
Removal of zero-skill workers would simply accelerate the trend toward using robots in jobs which require no thinking, such as ditch digging, trash collecting, dish washing, etc.
--Boris
When robots design better robots than you can, then what? Humans will simply cease to be relevent and I suppose shall be replaced. That's what you're advocating.
I'd suggest maybe implimenting a phased system where the more automation is happening the more abortions and other birth methods are increased. That way, we can make the transitition somewhat easier on us.