Noone says its revolutionary, its just different from other big GW games (Old fantasy, 40k, TOW). And indeed, its mostly people from there who complain about it.
I would pick alternating activations over priority any day, but thats not what the choice is, its Priority roll or IgoUgo.
Its just as far as GW is ready to take it for now, one day they may ditch it and go AA, just as one day they may ditch d6 purity, or to hit to wound sequence for something better.
Also, just some of my barely related thouhts.
Age of sigmar is not really a tabletop wargame, neither is 40k from 8th edition onwards, they are video games, that are played on a table with dice, comparing old 40k and fantasy to modern 40k and AoS, is akin comparing Wargame:Red Dragon to Starcraft, or iracing to need for speed.
And indeed very little tabletop games are comparable to that, outside of maybe Malifaux, MCP, and maybe a couple others i fail to remember. And not that it goes unnoticed, frustration with that is often phrased by the old guard as "Magification" of the game (Magic as in MTG).
If you want to play a tabletop wargame as you would a video game (which is what alot of people want, and a lot of new people expect) AoS and 40k are your options due to their competetive popularity, not everyone got Infinity, or SW legions scenes, while warhammer is wastly more popular, not even talking about the amount of battlereports or any other kind of youtube videos. AoS is just simply more interesting and engaging to some people than 40k, and priority while not the sole reason, is a big part of that.
Maybe i would like to play say Battletech, the same way i play AoS, but not only the rules dont lead you into that type of thing, the popularity and community are iherently different, and playing it the same way i play starcraft, dota or mtg would be at the very least, inapropriate towards the community im playing with
(Not native english speaker, so not sure how much of that is clearly understandable, but i think most people get what i mean)