In my language we have an ancient term/story called 'Yaanai Kanda Vaadham' meaning the 'debate on the elephant' (the origin of the story is controversial so lets leave that out). Perhaps you have heard the story, four blind friends come across an elephant, each one holds a part of the elephant and equates it to what he knows and understands. Hey! there is a wikipedia page on it

http://en.wikipedia.org/wiki/Blind_men_and_an_elephant

When merits of processes are discussed devoid of its purpose (delivering quality software in business relevant time), the argument is similar to the story. The process is just the means of reaching the purpose isn't it? It is not like successful software was delivered only in the last decade, we have been to the Moon and back before that.

Unfortunately, processes are always made in good intention to achieve a purpose, this when transmitted from one person to another becomes a system, as there is no guarantee or way of enforcing 100% knowledge for all people in the chain. This deviates it pretty quickly from the purpose with focus only on the practice and soon the system becomes a religion.

Then surprise! people shed blood over it after that demanding that their book is the only truth :-)