Because it's a poorly thought-out policy created and pushed by people that may not (and clearly do not) understand the market, the space or the unintended consequences that arise from it.
>There are clear environmental impacts in desctroyiing functional devices.
And we also have clear liability and legal reasons for destroying 'functional devices'.
>Doesn't mean those reasons are necessarily in the interest of the public
Preventing devices that the manufacturer has not certified as safe from being distributed to the public is also in the interest of the public.
Every device that is currently made will end up in a landfill. Having the manufacturer and consumer responsible for these externalities is not a terrible policy, but this is not how you do it.
Why would it be wrong to make this practice illegal going forward? There are clear environmental impacts in desctroyiing functional devices.
Of course Apple has all kinds of reasons why this makes sense for them. Doesn't mean those reasons are necessarily in the interest of the public, so the public doesn't have to accept them.