Phones, Tablets, Mac computers, Cars, iTunes Music, App sales, Headquarter building, Share price, tax strategy. There are a lot of things that take up bandwidth of senior management. We've all seen many companies where something doesn't get the focus it could were it not for other priorities.
Is this absolutely the reason the laptops are a bit crap? No, but it is plausible that the lacklustre offering in hardware comes from the lack of it being a priority for the company. It certainly doesn't feel like a priority for them, and the offering doesn't feel like a lot of strategy has gone in to how it has evolved over the last few years - contrast that with the iphone.