Is it? Steve Duda has no choice, his lunch is getten eaten by Matt Tytel and the folks at Native Instruments. If he wants to keep selling his $150+ plugin, he better stay on the cutting edge.
For everyone else though, I find it hard to blame them. Overnight you get a complete architecture change that you need to buy test hardware for, test-compile for ARM, find out what breaks, source new ARM-compatible libraries for what dod break, re-write some/all of your codebase to account for these changes, profile the performance difference, re-evaluate if the native version is worth it, then set up a testing and CI pipeline for a second architecture. Since most of these plugins are written with the notoriously fragile JUCE framework in C++, I can see why it's not just an overnight task to get it working on Apple Silicon unless you drop everything and make it your top priority.