Sure, they say this NOW...

[Gaisgeil]

I don't think the bloodcurdling thing was supposed to mean they sounded bad, just... exotic. If you ever see footage of Scottish troops in formation marching or charging under the sound of the pipes you can see what they're talking about. For some reason, it's intimidating in much the same way as if you or I were in the jungle and starting hearing native drums like in the movies or something, it's probably a combination of the fact you're already in a war, so you're constantly on edge and you're confronted with something you don't understand, that's a recipe for fear! Besides, the pipes for some reason just invoke emotion, whether it's pride, fear or tranquility (think funeral pipes) people (and some animals! just ask any piper who's played outside) respond to the pipes.