> eliminating stick drift would certainly reduce some number of repeat customers

Someone experiencing stick drift - there is no guarantee they will come back to the original company for a fix. In fact they may well go elsewhere.

Eliminating stick drift, and as importantly eliminating reports of it happening, can only enhance your brand. Better build reputation = more sales?

What we don't know is (1) the cost of a Hall Effect sensor and (2) the replacement cost to the company. That would seem to be the maths that matters.

I know I put off buying a Switch in part because of drift reports.