If you're placing the iMac in a brightly lit location in the home where there are lights or windows directly behind you to reflect off of the screen then obviously you need to find a better location to put the computer if you want a 27" iMac.
Perhaps I should move into perfectly black basement? Even then I will still see my glowing face in it.
In my opinion, it's a no brainer and I think Apple should give people the option (I would gladly pay more), rather than making them remodel their house around a computer.