The product management tips blog wonders whether product integration decreases usability, because it leads to an abundance of functionality in one product:

So what has probably happened here - Toyota had to create this one product that integrates the GPS, CD changer, the blue tooth telephone, the trip information and the other 15 things I have not discovered yet. It probably started as one component, which then had to be reworked to integrate the second component and so on. When everything was said and done, we have what I get to use now.

See also the follow up on that post by product management insights.

(Illustration: the product management tips blog)