Liability issues
I recently replaced the battery pack buried deep within my Surface RT 2. Successfully!!
It was a frightening combination of Watch Repair and Bomb Disposal. It was many times more difficult than the iPhone 3GS I did years ago. More dangerous too, huge cells glued in.
"...what I do have are a very particular set of skills, skills I have acquired over a very long career. ..."
If such a repair had been attempted by anyone without the complete set of skills and knowledge, they'd have had a flaming lithium battery burning holes in their dining room table.
Such 'Combination Watch Repair / Bomb Disposal' battery replacements shouldn't be widely encouraged.
It'd be nice if they were designed like Cordless Telephones. One minute job.