[mxcl]

It's not that I hate sudo. But I encourage people not to use it because:

1. You're adding to OS X. It's very important that stuff that gets built definitely didn't touch any files in /usr or /System. Build systems for some projects are big pieces of half arsed software. It's quite a risk — and an unnecessary one at that — to trust them to not break the bit of the system that only Apple fully understands and controls.

2. Homebrew is for developers. I dev software. Mostly I am installing x library and will want to upgrade and fiddle with it readily. Sudo is basically unnecessary for most of Homebrew's packages. Although I agree some stuff should probably not be installed without a sudo. But with Homebrew at least you can decide which to do on a per package basis.

Also, this isn't rationale, but it's still worth pointing out: most people install software on Mac without a sudo anyway (eg. almost everything in /Applications), so it's not such a big step to suggest you do the same for the handful of tools you need that OS X doesn't provide.