The rationale they gave is that hate speech appears on these apps, because some of the microblogging sites that can be accessed via Fediverse have this kind of content. Based on this rationale, I look forward to Google Play removing Chrome, Firefox, and all other web browsers from the store as well.
The only way they can define and enforce "hate speech" policies is by torturing the language, the definitions, and hoping no one looks closely at the resulting policies. In the US, beyond explicit calls for illegal behavior (usually illegal) and kiddie porn (always illegal), we don't have many restrictions or even a legal definition of "hate speech." But even those laws aren't consistently applied. For the most part,…
>The only way they can define and enforce "hate speech" policies is by torturing the language, the definitions, and hoping no one looks closely at the resulting policies
The rest of your comment is about the first amendment to the US constitution, which constrains governments (US Federal and state governments), not private parties such as Google.
Google would be well within its rights in the US to ban all hate speech from all the platforms it owns.