The devices aren't being disabled, they're just having their access to Nintendo's online services restricted. This practice isn't anything new, and has been around as long as internet-enabled consoles have.
"permanently ban those consoles from Nintendo's network."
"a banned console will stay banned from the network permanently"
Just like the other consoles on the market.
So don’t buy those consoles second hand. Again, exactly the same as PS and Xbox.
It took many years but Steam changed their old refund policy after a judge in Australia noted how criminal the old one was where they gave themselves permission to steal indiscriminately from consumers seeking refunds and used their imaginary authority to steal from an estimated 20,000 Australians. They actually stole from people all over the world but seem to have gotten away with it everywhere else.
If there was some form of serial #check system (like a car's VIN) for the consoles, then it would be harder to re-sell disabled consoles; still wouldn't prevent people from trying to re-sell them, but it would make it more firmly a case of fraud on the sellers' part if they lied about the serial#.
Switch hardware will likely be resold for decades so it's obviously going to be onerous for consumers that the devices may be invisibly crippled just because they want less copyright infringement.
They don't even need to ban accounts permanently, it's pretty disproportionate when you think in years and decades of a device's life.
You wouldn't have your save games but if you're setup to run unlicensed copies of games maybe you can also transfer those?
How can a resold device be trusted, no matter the owner?