[n3k5]

If you're in a dim environment, a glossy screen has slightly better contrast and colours. If you have a light source or bright objects nearby where their light falls on the screen, a glossy screen has significantly better contrast and colours, as long as the screen and you are positioned such that you don't see the reflections. If you can't avoid reflections, e.g. because you're outside in bright sunlight, a glossy screen is pretty much useless. But if you mostly have a notebook so you can take it to different indoor workplaces with suitable lighting, and/or so you can move from your desk to a couch or bed (e.g. to watch a movie), the reduced glare can be very nice to have.

So the thing is, if you never had one yourself and only observed others using them while away from their preferred work spaces, chances are you've literally seen glossy screens in a bad light :)

Of course, if your use cases are all text based, the potentially better picture quality of a glossy screen is indeed rather pointless. Either option is a compromise; what's better depends entirely on where and for what you use the device.