I'm not a Ticketmaster fan from back in the Pearl Jam days, but I think there's a misunderstanding in a lot of these comments. If you are just the platform that venues use, and someone asks for a refund, it's pretty heavy for the platform to be on the hook for the full cost right now (due to a massive amount of refunds). In the short term it can effect your cashflow (covering refunds to consumers while you try to collect from the venue), and in the long terms it could be a huge loss if you're unable to collect from a significant amount of your venues (money already spent).

In general you probably wouldn't want to hold excessive amounts in reserve from the venues because it could be a huge negative factor for them (money needed to setup the event), but right now with Coronavirus it's gotta be really messing with them.