Change my mind on this. I can't think of a single tank who's capable of bursting me hard _without_ building some damage for it that I'd consider a healthy champion.
Champions that started out as primarily sustained damage threats and became bursty - notably after the tank reworks - are also champions that have been an absolute menace to balance between said burst damage and their CC. Sejuani is losing her CC for more burst damage*, and Zac has already lost all his damage to retain his CC. Maokai, which happens to be the least offensive tank of the three, delivers his damage out in steady rotations. Farther back, Nautilus got changes that shifted him from DPSing people down with his W to chunking you with his E, and he's been a mess ever since, one that Riot is still hesitant to address.
Sion bursts you obscenely hard and we've had him become a recurring issue in top lane where he just becomes the top laner. Either with E max or Q max, either one leads him to hitting you with obscene chunks at a time. Poppy has a fairly good situational burst combo but over the course of a fight her damage leans into sustained threat, and she's been relatively minor on 'balance issues,' I'd say. Ornn? Bursty; huge problem champion. Galio? Bursty; huge problem champion. It's hard not to notice the trend that tanks being capable of chunking or outright killing you in a shorter span than before, on top of them having more CC than they used to, is a glaring issue with Riot's new tank designs.
This isn't to say that DPS-minded tanks aren't problematic but it's usually because of unrelated qualities. For example, Shen's global presence and Tahm's W used to save allies have made them much more troublesome than their damage outputs. Rammus and Malphite are DPS-y but they only get out of hand in very AD heavy metas, which is what they're supposed to do.
So, I'll repeat; tanks should be sustained threats and not burst ones.