You are painting agencies with overly broad strokes. I used to help lead the paid search group at a top search agency. Rest assured we did not try to pass off clicks as anything but that. Occasionally we had clients with branding goals and we worked with them to make sure we were adding incremental value, but most were direct response (ie. "Show me the money or you're fired").

A percent of media model isn't perfect, but if a client isn't seeing results, the relationship won't last long, and word gets around.

Now, there are scammy agencies out there, but it is hardly the norm. I loved stealing business from them because it was shooting fish in a barrel with all the problems on those accounts.

Be careful about making such broad, and highly inaccurate statements... They really don't help paint you in the best light.