Asking is cheaper than performing the experiment. The asker probably can’t afford buying one matte and one glossy monitor just to try them out. They also might not know anybody else with the other kind of monitor to compare with. That is especially likely if they’re buying a laptop with a built-in display – it’s unlikely that they’ll know two people with that model of laptop, with the same size of display, but one display matte and the other glossy.
If glossy gives you headaches and matte doesn't, does it matter how many people prefer glossy?
-- Some experiments are non-reversible
Damage to your eyes, for example. This is one area that asking for peer comps should not be crtiticised as just being lazy. Pay it forward, and all that. IMHO.
