The OPs point still stands regardless; unless for whatever reason you think you'll get 1) a windfall of stock grants that are 2) calculate from some actual monetary amount divided by the current stock price, you want the value of your stock to go up.
This is in contrast to actually purchasing a stock on the market.
So when the rsu has vested, it is converted to normal stock, where you can sell on the market for cash?
With the smaller Google-specific "well but" limit that insider trading rules restrict employees from trading in the company stock except for narrow trading windows after the company's quarterly reports.
Starting up interesting long-term projects and then canning them at the first sign of a cloudy quarterly forecast is not how you compete for top talent. It just makes the entire company look spastic and irresolute.
Google/Alphabet is in a good position to build the next Bell Labs. Instead, they're building the next Lucent. That's a bummer.
As you allude, Google's ability to deliver depends on the share price. While they are free from activist shareholders, they aren't free from competition for talent. A rising stock price keeps employees happy. Employees with lots of out of the money options get jealous when their friends experience IPOs.