Peering Policies and Route Servers

(2) Could anyone share opinions/facts regarding why organizations may or
may not exchange routes via the Route Servers rather than direct peering
relationships at the NAPs?

  I know of no case where an organization "may not" exchange routes
  with the Route Servers.

I did not mean to imply that an organization was "not allowed" to exchange
routes with the Route Servers. I was trying to learn why an organization
"may choose" or "may not choose" to exchange routes with the Route Servers
rather than use direct peering relationships with other organizations.

In other words, what is the value for an organization to utilize the Route
Servers? And if there is value, why is everyone not doing it?

Ali....