From my perspective TiaWT is nothing more than an "oh shit" button and for the most part has always been. In the early stages of PanZ it was a bit oppressive, but this wasn't because of TiaWT's design. Namekian at the time was extremely oppressive given its ability to push all three victory conditions efficiently. At first, it could achieve two of those victories without ever entering combat. The only way to really win was to get in one or two really good combats, capturing a few balls and gaining an advantage on Life Cards. However, Namekian could efficiently cycle TiaWT over and over again. Hell, by the end of set three I played a Slug deck that damn near could use TiaWT every turn. So for the most part, I think most TiaWT protesters are still experiencing the bad taste the early state of PanZ left.
However, by the end of set 6 TiaWT, while in every deck, did little more than stall for a turn. In many cases, most of my decks including some aggro would still win despite a TiaWT being played. While I understand it's in everything it doesn't define the meta. If it disappeared today, it wouldn't affect any of my 30 decks at this point. Even Namekian decks that continuously recycle the card would just recycle other things and continue to have what equates to 100+ life card decks.
There was a time I would say TiaWT could be consider oppressive, troublesome, or even centralizing, but it isn't at this point.