A bit of research reveals a more complicated story going back several years.
Part of the problem is that these events are free to view, making it difficult for organisers to raise the money needed to cover costs. They've been subsidised by the public sector, and as a taxpayer, I'm against funding freebies for motorcycle fans when nurses are being asked to pay for inflation.
Motorcycling Ireland also blames Brexit: previously the event was insured by a European firm, who withdrew. (Since Brexit significant numbers of European firms have chosen not to do UK business because they can make money elsewhere without having to do a lot of border paperwork.)
Unfortunately, after they withdrew, Motorcycling Ireland were unable to find anyone prepared to take the risk of insuring Irish events. (Usual cause of insurance companies refusing business is a bad accident record. Have any recent motorcycling events resulted in any big claims?)
Seems to have moved on since then, but the lowest quote received was £400,000, which was too much for the clubs.
I think it quite right that bystanders injured by crashing motor cyclists should be recompensed. If I'm hurt or my property is damaged, I expect someone to be held responsible. Big payouts and prison for negligence or wrong doing.
It's not that society has become more litigious or risk averse, it's that people are being called on to pay for blunders. Should anyone expect the taxpayer or Insurance companies to cough up when fans don't? Nothing stopping them from sending money to Northern Ireland so that motorcycling events can continue.
Dave