Is it intentionally hostile on Apple’s part to bar androids from joining? Yes. But the reactions from Apple users aren’t entirely unjustified
The reaction from Apple users is to blame Android users - which is entirely unjustified.
But of course, post purchase rationalization and brand loyalty play a big part in why people want to externalize blame rather than questioning their own decision or blaming their favorite company for providing a shitty cross-platform messaging experience.
Not all iMessage features can be mapped to RCS, so unless Apple brings iMessage to other platforms, non-Apple phones will always be associated with an inferior messaging experience.