Thats easy to say, once you learned to hack the system.

But many brokers do take money to simply show you the apartment and nothing else.

They are the "1-click" brokers. The experience doesn't mean that they aren't a part of a complex system. We usually applaud efficient systems don't we?

15% is justified because people pay it.

That does not make it justified by any meaningful definition of that word.

more significantly, the major NY brokerages have managed to keep a real MLS from forming. every other US market has multiple listing service, but in the city its been killed and any attempts (like VOW) have been effectively squashed. this is for sales. rentals are small change in comparison.

NY has a significant rental market.

yes, but the big money for the brokers is in sales. most of them want to concentrate on representing fancy exclusive sales.