[moogly]

I should've said accidental damage. Dropping the guitar. Knocking the stand over. Shipping damage. Guitar trauma, basically.

Tuning pegs don't really tend to fail. Unless you have those "vintage" Les Paul-style ones (yuck), but they're easy to replace.

Frets get worn down, necks tend to bow or arch, or at worst warp (more seldom). Fret recrowning/redressing, truss rod adjustment and fretboard leveling are part of the regular maintenance of a long-lived electric guitar.

Now, headstock breakages are usually pretty easy to fix for a luthier, and the result is stronger, since a glued joint is stronger, just not as strong as a glued scarf joint.