Yes, even limiting kb articles by customer based on the products they have would make the whole KB more useful to the customer who would not have to search through everything to find solutions.

This could also be handy when you have different customer groups, i.e. Business or Home users. Or other segments who need different info in the KB because they are using the product differently.

And of course the main case above would be useful - i.e. ultra custom KB for a high value client.