It sounds like a mix of good intentions, misunderstandings, and poor communication.

Shopify wanted to put in place better goverance and access control, to reduce the risk of a supply chain attack and put a deadline on that.

Part time maintenaners left it to the last minute, didn't consult or communicate well and then over exerted their influence by taking over things without consensus to do so.

Existing maintainers then rightfully alarmed, when it all could probably have been handled better.

Doesn't help that the rift over a competing tool being created probably played a part in some of the heavy handedness. DHH's drift to white supremacy probably hasn't helped either, but likely neither are the cause here.