The doubt without proof is maddening

I assume you mean doubt about systems and their efficacy? If so, it is not "doubt without proof", but just an acceptance that roulette is a negative expectation game, and no manipulation of stakes or selection of bets in the random game affects this, that is all the proof you need to "doubt" ANY and ALL systems. This is not arrogance, but just a recognition of mathematical facts. The accusation of arrogance stems from the lack of understanding that the NE applies to ALL systems. The system advocate thinks that every system XYX must be tested before passing judgement. Any system, according to him, has the POTENTIAL to be a winner, and only testing can sort out the wheat from the chaff. So to write off ALL systems seems like mere prejudice and arrogance. He fails to understand the universal applicability of the negative expectation and how it's not affected by money management and bet selections.

Those who favor advantage play - the application of physics to roulette - may be equally frustrated by system players who doubt it. "Where is the proof that it works?", they ask. APs can't prove mathematically that their methods work, and they also can't prove mathematically that they DON'T work. But in the case of systems, there IS mathematical proof that they don't work and the only assumption for this proof is that outcomes are random.

You cannot beat the random game by applying rules WITHIN the random game, but you can step "outside the box" of randomness to another world which isn't touched by the proof of negative expectation.