This is a ton of money and I reckon they could last a long time on it, but I believe the investor-mindset is something like "if you're not growing, you're dying" and if you're dying, you should probably sell at your peak. Looking at Yahoo revenue, it's clear they're dying and as a result, I wouldn't paint this as just greedy investors being greedy.
Theoretically, a stock price reflects future earnings. If future earnings are constant, then the stock price doesn't move.
Why buy $1M in stock if you know 5 years from now it'll be worth $1M?
Also, you'll be getting steady income from dividends.
Also, in the bigger picture you're less likely to be dealing with a manic depressive cyclical market that gyrates wildly between extreme growth mania and extended depressive episodes.
What you don't get is a monkey-brain dopamine kick from telling yourself that you're an awesome person who beat the market.
It makes investing predictable and drama-free, and where's the entertainment in that?
I feel that's the core problem with the stock market. It was supposed to be about investing in a company in exchange for the share of the profits (dividents). Instead, people got greedy and now it's gambling; nobody cares about the company they invest in, everyone plays meta-games.
A lack of dividends is hardly the stock market's problem, though. Assuming that is actually a problem (I'm not sure it is), it would be a problem of company managers and investors not understanding fundamentals.
It is entirely possible to overprioritize growth. Doing so can lead to overreach, spiraling costs, bloat, and loss of focus. But at least some growth is often required just to maintain a stable return.
It also bears mentioning that ther are many possible factors driving growth, some of them endogenous and some of them exogenous, some of them cyclical and some of them secular. It's very hard to speak of the blanket term "growth" as being particularly meaningful, in and of itself. We need to be specific.
Once you look at the incentive structures that creates, the mania becomes disappointingly rational on the part of investors.