How to have a bike in San Francisco without it getting stolen ?

Damn theives!  They don't improve life at all.  The weasels can get nearly any lock off.  Take your seat with you.   I used to have little alarms that cost 50 cents.  They had a loud alarm and one pin that when ties do something kept it quiet but any movement that pulled the pin out screeched a huge noise.  Noise can repel the POSs. A gal I knew in NYC would carry her bike up 4 flghts of stairs when she came to visit.

Buy cheap bikes that have no resale value but get you where you want to go.

You don't leave it outside.  You bring it indoors, everywhere you go.

AJ has the only real answer. The other fools seem to think that bikes never get stolen anyplace in the world but San Francisco. That's what happens to you when you shovel alt-right garbage into your brain 24-7

Any big city has more property crime than any small town.  The law of averages applies.

Many people take their bikes inside businesses with them.  You could also watch your bike while inside and be prepared to confront anyone who you see touching your bike.  

While I'm sorry you lost your bike this post is as you say a rant and it really has nothing to do with travel.  The same thing could have happened anyplace.

San Francisco; the liberals utopia.

Trying asking Nancy Pelosi about it.

try having a bike somewhere else. Like Georgia  or Texas or Arizona