The point is that now you’re descending into nonsense. If we cannot use rational thought to decide what to do, but instead have to trust some old irrational idea, which idea is the correct one? Oh, ‘someone’ said that television rots our brains. Ok are all the rest of their ideas good? You are likely to find the answer is no.
Entire cultures have deep respect for their elders and are highly conservative in that whatever advice their elders give is treated as a good idea. This works except when it turns out that the ‘elders’ have 10 different incompatible bits of advice, or things that simply don’t work at all.