I've personally encountered whales in two situations:
One was someone in an MMORPG trading equipment. Okay, I kind of get the skipping work part, especially if the money doesn't matter.
But then there were the logs I've encountered while doing support for a browser based MMO RTS. Players clicking the same few buttons to get a small fixed amount of resources. Over and over and over again. Only interrupted to recharge the currency. How can that be satisfying? Just the "work" alone seemed demoralizing to me, but then even paying for that?
Have you ever experienced something like this? Is the process of spending enjoyable? Or does the end justify the means, especially for non-random outcomes?
The fun part (and what distinguish the good gacha games from the bad ones) is how much fun you can have with what you get. Some feel like the transactions and the gambling is the end goal. You play to get currency to get random stuff. Boring.
This seems like a strange measure to me. No judgment on how you choose to spend your money - I've certainly spent money on things I later regret, and I've also spent large sums on relatively frivolous things which I don't particularly regret. There's always an opportunity cost though - I could have spent the money on something else, I could have saved more, I could have given more to charity. Over time I try not to repeat the expenditures I regret and focus more on the ones that I don't.
It works like that, except you usually still have something for a long time, even though it's digital.
The key is in your last sentence: "wouldn't in retrospect have preferred to use that money for something else."
Unless I went and blew 50k on the game (which I fortunately never did and likely never will!), that's not even a question. Whatever money I'll spend on these, I -still- have to spend on something else. I only spend a tiny fraction of my disposable income. I (and many "whales") just have a LOT of disposable income. Very few people who go and blow 1500 bucks in a night on these actually empty their bank account (at least from my experience being part of a lot of gacha game communities. I obviously don't talk to all the whales).
I have a kind of "limit" I set myself, with zero expectations. When you blow enough money, statistically the odds of getting what you want are really high. I've gotten really unlucky at times, but usually I'll get what I was whaling for. And sometimes the game shuts down, and it's like, whatever, it happens.