because they are usually thicker, string your acoustic with lighter strings if that's a problem
The strings themselves are thicker and also the action of the strings is set higher from the fretboard than an electric...pretty much common sense
Ibanez RG 770 Deluxe
Epiphone SG Custom
Marshall TSL60
Digitech Whammy 2
Electro-Harmonix Deluxe Electric Mistress
Boss PH-3 Phase Shifter
Boss MZ-2 Digital Metalizer
Boss DF-2 Super Feedbacker & Distortion
Boss XT-2 Xtortion etc