|I'll put one more vote in the "this was a silly idea" box.
Some routes probably do deserve a bit of retrobolting - but to me these are the routes that have potential to be classics, but because of poor bolting get zero traffic. Wasted prime real estate. The Eyrie is not one of these routes, it gets heaps of ascents and by and large everyone loves it just how it is. I like doing a bit of research on thecrag.com as its almost the only way of gauging the 'general climbing publics' views on routes. It's had over 300 ascents by thecrag.com users in the last 15 years and the keywords people use to describe it are "hard, fun, cool, nice, fantastic, good, sweet, amazing, great, lovely, classic, awesome, super, beautiful, rad, exciting, enjoyable, exposed, crazy, short, easy, cruisy, traverse, slabby". No mention of it being some sort of death route that requires fixing.
Chris Baxter once said to me that people underestimate beginners. It might have some 5m runouts but by and large the average beginner really won't have a problem with that. It's a good head game, and the lack of prior accidents seems to confirm that it's not an overly dangerous route.