rant: cancelling competitor registrations

something has been bothering me lately.  you see, i registered for a seminar, then a few days later go this:

argh.  it wasn't rude necessarily, the individual politely is asking me not attend and for the reason.  i just found it very "un-tech-community" of this particular company.  i wonder how people would react if microsoft canceled registrations for competitors attending pdc or teched or things like that?  surely they would be /.'d.  in fact oscon, railsconf and other open source conferences never do this -- and those are the audiences that don't like big blue.

what do you think?  maybe i'm over-reacting.  maybe not.  it just made me take a tums when i read it, that's all i'm saying (especially since the registration for the site said nothing about requirements).