People might not have asked for it, however the Devs seemed to think it was enough of a problem to try and mitigate this issue.
Crit fluctuation is going to become more of an issue if the job has access to an action that is much stronger than the rest of their kit. In the case of Samurai, Midare Setsugekka comes roughly every 17 seconds. SAM's 3 step combo averages at 287 potency per GCD, in 6.11, Midare is 640 potency, this one attack does more than double the average potency of your normal GCD combo and that is before the guaranteed crit. By making it a guaranteed crit, the devs are effectively making the RNG on crit variance always in your favour, which lessens the gap caused by RNG. If you go back to before 6.11, when Midare was 1200 under Kaiten, you can easily see how a potentially 1800 potency attack (assume a 1.5 crit multiplier) can sway your damage in a massive way (note that the removal of Kaiten does not matter here, Kaiten could have stayed, still powering up Midare and keeping the guaranteed crit).
However, effectively turning Crit into another Det is not the solution. The problem is with the critical stat, that with it being able to increase critical rate and critical damage, making it far superior to any other stat except your main damage stat. There are probably numerous ways it could be changed, however, something that could be done is splitting the 2 effects of Crit, so you have a crit % stat and a crit damage stat, however, rather than adding another stat, you could potentially rework a current stat, like Direct Hit. Direct Hit could be the one that increases your crit rate and the critical stat could be the one that increases damage. This then gives you flexibility in how you want to distribute stats. If you have a job that has a high amount of guaranteed crits (Warrior), you might favour crit damage, if you were a quicker job, you might prefer crit %. Of course, this does mean getting rid of Direct Hits as they are now, but I don't see that as too big of an issue. As for crit skills, you could make them either affect rate, damage or both (best option), this then means all jobs will benefit from crit based actions again.