UWS as a REST protocol

[Roy Williams]

I would like some understanding here. I am seeing some sensible and 
reasonable argument, plus some quasi-religious material about the nature 
of the True Spirit of RESTfulness.

The part I understand is about using URLs in place of SOAP calls. So 
that all kinds of things can be named and cached and sent in email and 
as soon as you click they come alive. VOSpace objects and dynamically 
computed image cutouts and other sorts of service calls. SOAP is a 
necessary evil when requests and responses get complicated and we are 
forced to the complicated protocol.

But then there is the religious part. Why can't we have verbs? Like this:
http://blabla.edu?service=cutout&POS=301,22&recipe=bombayduck

The clergy of RESTfulness want this to be written some other way (is 
that right?)
http://blabla.edu/cutout/301/22/bombayduck

What is the theological basis of RESTfulness?
Why is it better than VERBishness?
Why is is bad for a URL to have side-effects?
Why can't VERBish things be cached just as well?

Roy