This is just a theory, so bear with me (constructive criticism is welcome)
And this theory asserts that Bitcoin dumps like what we've seen recently (i.e. today and right after the rejection of the Winklevoss ETF by the SEC) contribute to more even Bitcoin distribution over time and will help stabilize prices in the future (read make Bitcoin growth more consistent). What real world facts is this theory based on? We know that initially there were only a few users (so-called early adopters) who held the majority of coins, so they could easily move the price by dumping their stashes (at least, some part thereof). In the case of the lack of major news (either positive or negative), the price is pretty stable right now. So the only viable explanation for all of a sudden price crashes is most likely someone dumping huge amounts of coins (maybe, the bros themselves). This causes the price to plunge (even if momentarily). It is almost certain as well that the coins dumped are bought by a lot of independent traders, and therefore the wealth distribution is set to level out eventually. That's basically why dumps are important since they are caused via massive sell-offs by a relatively small number of large Bitcoin holders and get absorbed by the market
After reading your post I've voted "Yes, they are". You have a good point, I have never thought about this issue that way. If you are right, and hopefully you are, the dumps work to the benefit of Bitcoin because it is dumped by a few and adopted by many
But this theory is still not without its weak points
For example, while it is certainly true (well, at least, I think so) that unexpected, out of the blue dumps are caused by cryptowhales liquidating their stashes, but what about pumps? It could be said that pumps are in fact offsetting the leveling out effect of dumps. And while dumps contribute to more even wealth distribution, pumps certainly work in the opposite direction, i.e. contribute to wealth centralization (accumulation) in fewer hands. That challenge in its turn could be somewhat refuted by claiming that pumps necessarily cause price hikes and thus their effect would be less pronounced since with higher prices you would just need more fiat to accumulate the same amount of bitcoins. Further, dumps are more profitable overall, so they should be preferred in case of the price rising. For example, the twins bought 100M dollar worth of bitcoins at the price of, say, 600 dollars per coin, but to buy the same amount of bitcoins today they would need twice as much cash. Therefore, with the same stack of dollars they could buy only half as many bitcoins today, and that would work against Bitcoin wealth centralization at higher prices. The bottom line is that higher prices make wealth centralization less likely at large