I disagree that making your device easily serviceable necessarily makes it less attractive to that portion of the population. I think that making your device brittle, fragile and easy to tamper with makes it less attractive to that portion of the population - having open documentation about the ways to approach repair and then letting the electronics repair shops all be able to repair your device makes it really attractive to pretty much all of the population.
If your ease of repair comes at the cost of quality people will complain about the lack of quality - but nobody specifically wants something that can only be repaired by one market entrant that has full control over the price of repairs.
Also, if you really want to emphasize quality you can run a repair certification program that distributes high priced stickers to aide in people's confidence.
I think the point was that making it easier to repair will compromise something like device size or weight, making it less attractive to the larger portion of the population.
If they could provide the same form factor and make it easily repairable, then I think you would be right that would be attractive to all, however I think small size and repairability are mutually exclusive properties.
Ten minutes watching YouTube will demonstrate that amateurs are certainly capable of repairing todays devices, even down to something small like an apple watch, so small size and reparability are clearly not mutually exclusive. Why would they be anyway? Certified repair technicians aren't magic, they just have access to training, parts and tools that help.
You should see the insanely tiny pads I had to solder to on my Xbox 360 to install the RGH mod. With a 10$ solder iron, homemade flux, miracle I was able to do it. But I did repeat it and given the same incentive even if they made it smaller next time I would get some jewellers glasses and a better iron.
If your ease of repair comes at the cost of quality people will complain about the lack of quality - but nobody specifically wants something that can only be repaired by one market entrant that has full control over the price of repairs.
Also, if you really want to emphasize quality you can run a repair certification program that distributes high priced stickers to aide in people's confidence.