Removed mine as there no use at all. May stop 1% of dust and boulders but what about the 99% that squeeeeeel when trapped 
For years I'd have said the same as you. But as Pudding pointed out in a different thread, they will prevent grease hitting the brakes if a CV joint spews its guts. Plus, if you're tracking a car, and generating a bit of heat, they'll shield your lines from the heat.
The rears... Mine are getting f*cked off as soon as I get the chance. All they do is trap stones/grit.
ETA... Just to ruin my argument, I removed them on the front when I got the Clubsports fitted. No issues yet...
