Rix Sidhu said he was "devastated" after the crash, which occurred in Stevenage on Thursday night.
"I've been running this for 10 years and we have never had one incident. We were raising money for charity, as we often do, and there was no speed element to it," he said.
He said the meet was held in a car park with a speed bump at the entrance. "But unfortunately some people went a bit rogue. We try and stop that, we urge people — urge them on social media beforehand — not to go out on the roads, not to risk injury or anything."
The crash appeared to involve two cars, with at least one speeding.
Local Hertfordshire Police said some of those being treated were seriously injured after the cars crashed into the bystanders.
"There were a number of people in the area at the time and 14 people are presently being treated for injuries, some of which are serious," a police spokesperson said.
In footage caught on cameras, one car is seen turning in from a side road when another speeds past and clips the slower vehicle, sending both veering off in opposite directions.
The crash happened during a Cruise Herts car meet — a group for car enthusiasts which has been holding regular events for 17 years. Sidhu has declared that the events will now come to an end.
He said: "We've decided we're not going to run these any more. After 17 years, it's over. Some people like drinking and that sort of thing, we just like cars. They are our pride and joy, what we are interested in. Unfortunately this incident means we are all going to be tarred with the same brush — people will say we are boy racers."
He blamed the social media effect which made participants break the norm to get thrilling footage and post things to their friends.
Police have appealed for witnesses and called for footage of the incident.