The 15M situation was a catch-22.

- When they proposed solutions they were called out as being "politicized". Both left and right-wing saw them as biased (in the other direction of course).

- When they didn't propose anything, they were called out as being gutless (as you said), lazy, whiny...

- When leaders tried to step out they were criticized as opportunists trying to kidnap the movement for their personal interest.

- When assemblies were formed, they were criticized as slow and not effective (which they actually were).

Of course all these criticism were promoted from the media to form mass opinion. In case you didn't like a statement, you had the contrary to criticize 15M as loud as you wanted.

In the end nothing happened.