I doubt that there is any correlation between search engine and decision quality; the more logical (at least to me) conclusion from that sentence is that he is actively avoiding understanding competing products.

Perhaps he should focus on making products that convince his children to switch from Google/Apple products instead of banning them outright. They might be a good barometer.

This reminds me of the Broadway show producer who let his 10-year old kid watch new productions to gauge whether he should stage them or not. The idea was that the average audience has the same level of intellect as a 10-year old kid, and when the kid liked something, the general audience would too.

Related, but not the same, is the monkey which throws darts at a poster on the wall to decide which stock to buy. Who needs financial analysts?

That's a good observation. Why does he even need to ban Google/Apple products if the Microsoft ones are that good?