It's obvious that, like any commercial company, all they care about is to earn money. And forcing their user off an older product in order to make them buy again is... unfortunately too common and Ledger is clearly doing the same.
Nobody is forcing people to switch to new android smarphone devices but many people do it because phones stop working after few years, apps are not supported, etc.
You will notice that Ledger is doing exact same thing, but hardware wallet should not be the same as phones and communication device consumer products.
Ledger can always create new apps that will not be compatible with nano S and that would make it useless.
Also, something you both didn't say (or I've missed) : it also depends on how other software will behave. I mean that unless something fundamental changes or some big flaw is found, I don't see why Electrum wouldn't support the Nano S for many more years after Ledger stops updating it.
Answer to you question would be that you can't really use Electrum wallet now with older ledger devices like Ledger Nano, Ledger Unplugged and Ledger Blue.
On the other hand, first ever hardware wallet device Trezor One is still working just fine with Electrum, so you see the difference.
I am just saying that people who buy ledger nano S device now are basically wasting their money, clear and simple.