Is that 15 minutes for a first-timer, including time spent sourcing the upgraded display?

Very nice, and there's two paths forward for you:

1. Awareness that not everybody can or wants or dares to do that or be you. There's other people in this world! :)

2. LoL-ing other people for not being you

Entirely you choice! :)

-----------------

e.g. I can change tires and oil on my car and am aware that majority of people can't or don't want to - even handy, technically oriented ones.

There's simply a vast, vast majority of people to whom:

1. I'd happily recommend a ThinkPad because I think it'll serve a wide swath of people well

2. I would not come anywhere near suggesting they replace their screen; not only would that likely lead to disaster, but it'd 99% turn them off from considering ThinkPad in the first place.