Ask HN: Bad touchpads – hardware or software?

Why are typical laptop touchpads so lousy, compared to those in Macbooks? Is it the cheap (i.e. less capable) hardware? That wouldn't make sense to me: when you pay hundreds of dollars for a laptop, you'd be happy to pay a few (dozen?) dollars more for a quality touchpad and the manufacturers should know that.

Or is it the software - as in patents that prevent the manufacturers from offering the same smooth gestures with their drivers/software?

Anyone have an authoritative explanation?