On a different issue some charity runners do it got heartfelt reason.
The club runners I know fail to get in London (1/20 chance of getting in) and really only run for charity to get an entry.
Charities pay big money to London to reserve places. Its s big racket taxes should go up and most charities scrapped as a massive amount goes to making directors rich. To done of them it's just a tax free business. People vote for governments with low taxes then give £10 to charity and claim they are compassionate helping people.
Club runners have no reason to complain about any slow runners though as they should be able to enter on good for age times.