Only a luddite doesn't want to take advantage of technology to improve their own safety, but let's keep away from the obligation as it's a different construct entirely than the efficacy.
We are now at v.8 v.9 of the Bosch system and the new KTM version even works while the bike is cranked over. There are simply NO remaining arguments that a rider is `better` than ABS, excepting the rare scenario when the requirement to NOT have ABS means either the rider is a prick (stunting), or a prat (gone somewhere they shouldn't).
The point is that, just as a helmet on ones' head doesn't imply things are going to end well in a head-on with a 40-tonner, you have to train to use ABS, because the ABS capabilities only really come into play at the extreme end of the operating envelope. In s doing you teach the rider how little of the performance of their brakes they were using before, instilling the one thing that every rider needs -
confidence. A perfect example is riding in the rain - we've talked previously about how a rider lacking confidence in the wet usually makes all the wrong assumptions and rides so slow that the tyres don't reach operating temperature, which makes them feel squirmy, which the rider interprets a slack of grip, costing them even more confidence, which impacts on the riding in other ways. A confident rider rides faster and smoother, making for an overall happier experience, compensating for the conditions in other ways.
Things didn't go well for the Luddites...

No door is closed to an open mind.
Except a closed door, which a mind can't open, but even a stupid hand can.