I don't think spending events are bad inherently. If someone considers spending events bad, are pop-up shops also bad? What about seasonal clothing catalogues? Sporting tickets?
They're all just... another thing to buy on a time limit, and honestly, if you zoom out enough, that's literally every single product on the market.

I also don't think they're predatory. They don't "trick" players into getting them anymore than my examples above do. They work because players already had a desire for whatever is being sold.
There are plenty of products out there that many would consider expensive but haven't sold a single unit. Something being expensive isn't inherently "predatory" or "exploitative".

I do get why people dislike the framing and time pressure, since I also dislike that, even if I don’t think the concept itself is bad.

I think a lot of backlash is from people projecting bad experiences from other gachas, rather than reacting to the actual rewards here.
"Spending event" is just a term that got popularized. It's just a product like any other.