> however someone made a validator that resolves the logic to a specific class at runtime. So you'd basically have validator.validate(Object someObject).
> If I have a fruit which is an apple or a banana, I can't pass that to a method expecting an apple or banana. It can only be passed as a fruit.
You can by overriding the method on apple or banana. If your method is on some other object, then yes, you cannot do this unless your programming language supports multiple dispatch.
It's both hilarious and sad to see a bunch of 30-40 year old open source devs with mentalities comparable to Reddit moderators collectively bullying a 20(?) year old slightly immature dude.