It seems to me that the reason for this shift is the same reason manufacturers ship their TVs set to overblown saturation and brightness: it looks good in the showroom.
As someone who has no office and works every day either from home or from a coffee shop on a laptop, the glossy screen is pretty annoying. It's not impossible to work on it and you do get used to it, but my next MacBook Pro will be the matte finish. It's more annoying that a matte finish costs $50 more.