Aside from the usual thing about companies paying to have crapware installed on new Windows laptops, I'm guessing there's an economies of scale thing going on.

Aside from the usual thing about companies paying to have crapware installed on new Windows laptops, I'm guessing there's an economies of scale thing going on. Linux laptops ship enough fewer units that each one has to cover a much larger share of the fixed costs involved in getting a model to market.