It's Jurek's breaking several of the rules at Baxter State Park (Mt. Katahdin) that has done a lot of harm. BSP management has been looking for an excuse to send the Appalachian Trail elsewhere (and they can do this because of the unique statutes under which they operate), and Jurek's messing up just gives them more justification.
To me, going for FKTs with all kinds of outside support, much of it mechanized, defeats the purpose for which hiking trails were built. I can see those who do it unsupported (like "Anish"), but not where everything is handed to the so-called "hiker" on a silver platter.
As far as trail running goes, it's fine as long as runners wait for me to get off the trail safely (harder for me to do as I get older and have increasing difficulties with my balance) and don't try to push me out of the way, which unfortunately has happened half a dozen times. Trail runners might also consider the safety issue. To most predators (such as mountain lions), if it runs, it's dinner!
May your trails be crooked, winding, lonesome, dangerous, leading to the most amazing view--E. Abbey