Can't say I agree but your definition is relative to mastery and there is no doubt crit and mastery are closer together than crit and haste. However crit is always subject to rng, just because you increase your crit rate by 1% doesn't guarantee that you crit 1% more on a given encounter. It just means on average over all encounters you will crit 1% more. Whereas mastery is a guranteed benefit, you will do x% more damage without argument.
Mastery also increases our damage by 1.45% per 179 rating. It doesn't affect SW
and you are likely to have the occasionaly MF not benefit from it when bad luck with orbs. Still mastery is going to increase our damage by well over 1%, 1.2% is probably a conservative estimate. Crit only ever increases our damage by 1% when you move from 0% crit to 1% crit... as you get more crit the percentage of damage increase declines. Moving from 20% to 21% crit increases damage by 0.833%, so even with the trinket and factoring in more fiend uptime, it's not going to increase that value by 0.4%.