Why do people say "Initiative takes too long/slows the game down"?

Every now and then I see some posts on reddit, or videos on YouTube where people say that rolling for initiative takes too long and slows the game down, and propose new and inventive ways to make it faster.

Last time I played I decided to track how long it takes to roll for initiative and start the combat. It was a 4 players versus 7 enemies situation. Between the DM calling for initiative, rolling the individual initiative of each monster, noting them down, and noting the initiative of each PC, it took him 34 SECONDS. It's way less time than a single round of combat.

Multiply this for 3 combats in a 5 hour session and you have the total "waste" of 1m42s!!!!!

This being said, I really don't get where the perception that initiative is slow comes from.