Once you have decided to have a firewall in place (which you may think is evil, but I consider pretty much a necessary evil)
If by firewall, you mean "a box that can perform policy enforcement" then I don't think that many people in the IETF would think that's an evil thing. The problem is more that the general public seems to conflate firewall and NAT. Perhaps a new word is needed for "a box that can perform policy enforcement".
simon
-- www.simonwoodside.com -- 99% Devil, 1% Angel