That's when they're solo q...usually.
I solo q'd with her several times before, though. The first time I did so, I was very judicial and selective about when I decided to ult.
I told the support how my ult works and that I will use it if I feel that they might die if I don't do something in time. I even told them that I'll ping twice on the enemy, and I'll wait for them to ping it back for me to ult.
But I only said all of that in 1 game. The others, I pretty much used it under 3 circumstances.
1.) If my support is in crisis mode and need escape ASAP ( I saved my Maokai soulbound twice and yanked him out of a 1 v 3 when his health was around 100)
2.) If we're trying to go after the same target and they're lagging behind. Surprise attacks are fun, and it gets us sooner into the fray.
3.) If I am certain that ulting them doesn't interrupt anything meaningful they do. As I mentioned with Maokai, he was already going into a fight. I saw him W onto an enemy and snare. Since I remember how Maokai works, I decided to ult him then since he didn't really have that much of a combo move to do right then. We secured a kill, and it all worked out since we pretty much held the target in 1 position long enough to rip through them like wet Toilet Paper.
I feel bad that you had a bunch of experiences when a Kali ult ruined a play as opposed to making it. X_X I try my best to think about what I'm doing before ulting randomly. The range isn't global, and I have to rely on my partner to actually be able to do something meaningful. I'm not going to waste it on random BS
And so far, I'm glad to say that nobody has complained about my ult as of yet.