I find Kindred's ultimate to be fine as far as playstyle and mechanics go. The only problem is that she pretty much never survives a team fight in which she did anything remotely useful without using the ult, because she is just so short-ranged overall that she has to facecheck a frontline to do any damage. Which is obviously kind of counterproductive for a high-kite marksman.
The ult itself can be used in a brilliant variety of ways if the player knows their enemy comp well and has really good positioning. For instance, cast it on a high-health ally that isn't at risk behind you and then jump back until you fall into it - potentially deny most of the enemy team the invul and heal. Cast it in a bush or around a bend to bait people into a team gank when they chase you. Drop it under dragon to deny that enemy Fizz or Vi a steal, or even during your own steal to make them burn their smite with precise timing.
I love what her ult brings to the table, just have to think outside the box. The problem is her sh*t range forcing her to sponge and burn her ult, not her ult itself.