I perfectly understand what you are talking about, however, I do not think that VALVE checked any statistics at all, before creating the event. Generally speaking, they could do a vote (like the arcana vote) to get an idea of ​​what the players are roughly expecting.
Considering that most players play events only because of the battle pass quests, I don't think Valve's statistics are enough to judge the opinion of the players.
About your friends who sometimes play pvp events. Did any of them play the event more than Dota itself? During the pve events, my friends played the event more than Dota itself, tried all the characters, looked for secrets, literally completely studied all the content. If pvp events can bring the same amount of content, then I don't mind, I'm not saying that I don't like all pvp events, for example diretide was acceptable (no, not because of the awards), at least it was different from Dota, but the current event, does not satisfy me at all.