The common critique of Googles actions - the organization has profits, therefore there is no problem engaging in less profitable activities — strikes me as superficial.
It’s not about investing any given portion of revenues, it’s investing optimally. There are opportunity costs that must be considered in investments (and that means Net Present Value calculations).
Google’s revenue and profits are for the shareholders. When revenue is directed back into the business the question simply isn’t if the whole business will make money, it’s if this investment is optimally profitable considering all the alternatives. If a support engineer on Google+ generates $X over 5 years, but that same resource would generate $3X working on Gemini then dictating eternal Google+ support is robbing future Google of revenue.
Investments need to be individually justified, but also better than the alternatives to make fiscal sense. Even though that sucks for pleased consumers.
