Yes. It's only a matter of time before there is a backlash to Slack. I won't understand the backlash when it comes, just as I didn't understand the excitement. Slack is just a chat client. Chat has been around forever. Corporate chat clients have been around forever. What am I missing?
Honestly it's just the little details... which are huge. For better or worse emoji reactions and gifs really change the tenor of conversations. You can say its just chat, and that's true, but people are complicated and the smallest of chat features changes interactions so much. Just as an example, "heres a new feature" vs "heres a new feature (+100 thumbs up emoji)", for better or worse that changes people.
As did emoticons. I miss emoticons.