Kayle has a single target invincibility spell that has received numerous tweaks over the years in order to limit it's ease of use, massive number of potential applications, and to in general, remove its ability to be a catch-all "oh shit, save me" spell. Taric however literally just presses R when the fighting starts. There's virtually no strategy here. It has limitless defensive uses, and just as many offensive uses, and coupled with his aoe heal, he really has no counterplay. If all you can say to me is "well just avoid the stun and back off when he ults", clearly you are not playing at a very high level. A good player (hell, even just a decent player) won't give you the option to just "dodge". They will set up the ability so that either you can't avoid it, or so that if you do, you risk being caught out of position. There's no "poor decision making" going on here. The fights went as well as I've seen in a gold-level match (not saying that gold players are pro, but the vast majority of them know what they're doing).
Another thing to be said about Kayle's ult, IT ONLY MAKES 1 PERSON INVINCIBLE. This has counterplay written all over it. For example, you can either lock down the invincible enemy until the buff wears off, then kill. You can change targets to avoid wasting dps on the invincible enemy. Hell, you can even burst down kayle before she can use the ability (and given that she tends to build very glass cannon, this is quite practical). Taric's ult however has virtually none of these weaknesses. You simply CANNOT burst down all 5 members of an enemy team in 2.5 seconds. It just isn't going to happen, especially when taric is healing them all. Its possible to burst down taric before he can ult, but that requires focusing a very tanky champion while the rest of the enemy team is able to put dps on more valuable targets. And then of course, if he manages to survive the initial burst (which is likely given his innate tankiness and preferred items), he's going to ult, stun everyone, and then you're as good as aced. And I understand that separating him for the team (ie poppy ult) is a great counter to his playstyle, but this means that the team facing taric is required to pick into very specific champions for the sole purpose of countering him. Riot has said numerous times that this is inherently unhealthy for the game, and when it does happen, they either nerf the offending mechanic, or rework it all together.
To the guy who said that that we had a higher damage team comp. My team: Sej, Blitz, Ekko top (3 tanks) vs Panth, Morg, Kha'zix, Cait, Taric. Perhaps you've never played against pantheon, kha'zix, caitlyn, or morgana, but they would be what most players would classify as high damage. So, even without a tanky initiator (like sej, ekko, and even blitz they STILL had better initiation than us because of taric. They also had better counter engage than us because of taric. They also had better backline protection than us because of taric. They also had more sustain and damage mitigation than us because of taric. If you aren't seeing the pattern here, I honestly don't know how to help you. Taric is good at literally everything. He synergizes PERFECTLY with engage comps, aoe comps, protect-the-backline comps, and so much more. His only "weakness" is his disengage, but even then, it's only weak when you compare it to champs like janna, who SPECIALIZE in disruption. This game was NOT an example of a great player having a great game. This is a perfect example of a champion whose broken mechanics singlehandedly decide the outcome. Not to insult the taric player, obviously he did know what he was doing, but the benefit gained for effort used with this champion is simply too high to be balanced in its current state.