LCD prices much higher than a flat box.
TV box can support the resolution of the monitor is matched. CRT monitors can get better at any supported resolution display, LCD pixels are fixed, can only get better in the best resolution of the screen. Flat screen TV-box output size for 640x480, nothing for CRT, but the LCD, it will make the picture look very rough. LCD TV box output in 1024x768 above, to adapt to the LCD. It is because of this, liquid crystal box supports CRT and LCD, and flat-screen CRT only.