Well, you can get it, see here --> http://www.intowindows.com/get-windows-experience-index-wei-score-in-windows-8-1/
Personally, I wouldn't hold much value to the result. At best, I think it can only point to what is holding your score down. Number is almost meaningless. For example, I have a 4 1/2 year old computer, my wife a 1 1/2 year old computer. Both have Intel i7's, 8GB's of RAM, and SSD's for the OS. Her's, being newer has faster RAM, SATA III vs. my SATA-II, and other components newer. Her video card is a slower one than mine and has less graphic memory. My WEI is higher than her's as in BOTH cases, the video card is the lowest number. Other than in some games, like MS FSX which uses the graphics more, and performs better on my computer, her computer is clearly faster than mine.
Probably a reason MS removed it, the numbers really do not indicate enough to be useable in all cases.