I really don't see all the issues people are having with the Kensei tradition. Yes, you can't use them as Monk weapons, but you get other benefits. I see it all as being maybe less attacks a turn, for more damage. At level 5, instead of 3 attacks at 1d6+4, you could be doing two attacks at 2d6+1d4+4 each. That has much more damage potential (27.0 average). They are pretty even, as even without using pummel, 3 attacks with a Monk weapon averages out to 22.5 damage. 2 attacks with a great sword is 22. And you still have a bonus action to use for something. It may not scale all the way up to level 20, but it is at least very competitive for a lot of levels. Even a long sword in one hand is better for damage then a monk weapon until level 11 where it equals out. Then it increases in damage too. Throw in a bonus action Monk damage hand crossbow attack with Crossbow expert.
If anything, I see the Kensei giving you much more flexibility. Before, you pretty much always use your bonus action for that unarmed strike to maximize damage. Now you don't have to rely on it as much and have the opportunity to use your bonus action for other things. You COULD add a d4 to each attack. Or you could use a Ki ability such as Patient Defense or Step of the Wind. Use Sharpen your blade. Use a feat extra attack like Crossbow Expert, Dual Wield or Polearm Master. Maybe you multiclassed. You can cast a bonus action spell if you have spell casting like Hunter's Mark or Spiritual Weapon. Dash or disengage as a rogue. My point being, now you don't have to rely on using a bonus action to do a third of your damage.
I really wish I could combine this with Shadow Monk so I could bonus action teleport each turn...
It also has huge benefits for being a Monk archer. Now you have something you can use your bonus action for, adding a little extra damage on each shot.