You are mixing a lot of different things together. @Northern_Loki has already explained why there is different approach to each.
-
Seed runs were discussed already and the result of that discussion was that they are tl2+.
-
Auction terms are completely managed by auction organizer / seller.
-
Seed giveaways from sponsors simply can’t be hidden or tl2+ because sponsors want as much visibility as possible.
I don’t see why the latter two should be of any concern to you. If you don’t agree with auction terms, just don’t bid. If you don’t like to see sponsored category in latest, just Mute it.
There are still mixed opinions about advantages and disadvantages of influx of new users that has roots in sponsored giveaways. It would need detailed analysis to draw any informed conclusions.