But those are exceptional circumstances, and not the norm. My local parkrun is a couple of laps around a paved park. As someone who regularly volunteers because I love the atmosphere, I do NOT want to be standing around for 20+ minutes after everyone but 1-2 participants have finished waiting for people who can’t walk 5k in a reasonable amount of time. 20 min miles is a normal, not that fast walking pace. It’s the pace Google maps use as average.I've done some parkruns in over an hour because of the terrain. There was ice at Heaton parkrun when I first visited. I was fit enough to run it but didn't want to risk it.
Slowest was 1hr 12. Far too muddy and slippery to even consider running it.
There are also some parkruns that are challenging. My local is one of the hardest in the UK. Not unusual to see people come in over an hour.
Hardly inclusive if you have a cut off time.
I stand by the fact that if in normal conditions you can’t walk 5k at a normal pace you shouldn’t be at parkrun. There will always be uncontrollables like weather, terrain that affect speed, and I don’t think that a blanket 60m cut off is right but there absolutely does need to be some rational thought