The problem with this argument is that even with DH nerfed into oblivion, Tickatus Warlock still has horrendous matchups against Pure Paladin, all Hunter decks, ETC/Enrage/Bomb Warrior, Evolve/Enhancement Shaman, Highlander Mage and most Rogue decks.
Basically the only class that Tickatus Warlock consistently beats is Priest, but it’s already doing that so it’s unclear how nerfing DH would change things all that much. And of course, without DH slower classes could have more freedom to adopt a more proactive strategy instead of relying on defensive tools to survive the DH matchup, which could upend the whole meta all over again.
Maybe Tickatus Warlock will become a meta tyrant, sure. But so far, none of the data I’ve seen supports that argument, and I really don’t think Blizzard should continue nerfing things without data to justify it.