if we proceed to reverse-engineer MALI, logically it results in people buying more ARM products.
if people buy more ARM products, logically it results in more money (resources) going to support ARM's illegal and unethical actions.
any action which is taken that results in support or endorsement of unethical actions is, logically, itself, unethical
therefore, logically and plainly put: unless ARM's attitude changes the reverse-engineering of MALI is itself an unethical act.
So someone buying an nvidia card and using nouveau with it is by your logic unethical ? Tell that to rms he recommends old nvidia cards :P Besides I fail to see what else apart form more sales could convince arm to open their drivers.