One gripe of mine, Why no headphones?

Tablets are used as a media consuming device, and most of them have pretty standard headphones. For travelling and commuting, its not exactly viable for playing movies out loud. So why dont The likes of Apple, Google, Asus, Maybe even Microsoft dont provide you with headphones with the tablet out the box, why not? Your paying atleast over £200 for a tablet, i would like some headphones.