I think the person you're replying to is trying to make the point that people are generally OK with this, as long as it does not have an adverse impact on their personal lives. The hacker cloning the hard drive is likely to leverage this data to defraud or blackmail them, but Google et. al are not.
This is like the 'I have nothing to hide' argument against strict privacy measures. Individual bits of your information may not have much value. But the aggregate of all your information is something else. It may yield data that you don't expect it to contain. I can easily get your health, wealth, politics, relationship and even your exact address from it even if you never mention any of it. And the ways in which they can be used against you is also something you're unlikely to consider unless you're in a profession that does it - law enforcement, insurance companies, racial profilers, PR companies, lobbyists, ...
Another issue is that you are just worried about only your own data. But if Cambridge Analytica is any lesson, its that an entire section of a population can be targeted all at once using such data. And the outcome is no less disastrous than targeting individuals.
> They want some statistics. Not my personal information
I can guarantee you that's wrong - after the shenanigans they pulled to force me to register my CC and to prevent its deletion. But what's more pertinent here is that statistics is a sort of mathematical summary of a raw data. And that summary changes (into a different type of information) based on the statistical analysis you do on the raw data. I don't think you need an elaboration for this. But this is precisely the reason I believe that they will keep all your personal data in their raw form for as long as their resources permit.
> Maybe they want it for a good cause, who knows?
As they say, fool me once, shame on you. Fool me twice...
That's hardly a corroboration of your assertion. Google is a targeted ad company who offers free and paid services as a honeypot for personal data. Numerous prior incidents prove that. Giving them the benefit of the doubt is imprudent at this stage.
Maybe they want it for a good cause, who knows?
Would I really trust a random interneter over a company that has a reputation to keep? You overestimate my political biases.