This tweet, while in bad taste IMO, was a threat to those who are planning to continue looting and burning buildings in Minneapolis.
I’m not sure if you’ve seen the videos, but there are full scale riots. Rioters completely looted a Target and burned it nearly to the ground.
Is “shooting” the answer to that? Probably not. And hopefully the National Guard is not going to do that.
But at the end of the day, this is the commander in chief making a public statement, and Twitter is editorializing it. Make of that what you will.
The danger in the idea of "just find another X" is that, if you are willing to believe that the action in question justifies an open platform's prerogative to censor, then it follows that every alternative platform do the same. This creates black holes, if you will, that are incredibly easy for dissenters to fall down.
I'm not saying that I support Trump's message. But, as a society, we have to be nuanced about this and figure out what constitutes a right to use on massive platforms like Twitter. Twitter isn't just some dinky website. If you are worried about Russians/Chinese/Republicans swaying elections on social media, then you'd better be worried about how Twitter itself picks and chooses what you see.
After all, exactly how many levels down will we go?
Twitter: You can pay your own hosting fees.
Namecheap: Your users can find you at your IP address.
AWS: You can run your own server hardware.
Intel: You can build your own CPU.
Electric Co.: You can generate your own electricity.
VISA: You can take payments in cash.
Hospital: You can use your own butterfly strips and an ibuprofen.
United States: You can find your own country.
There are sort of alternatives to Twitter, though you have to admit that Twitter's approach and audience size is quite different from, say, someone's forum using vBulletin. Nevertheless, there are mainstream alternatives such as YouTube, Facebook, Instagram, and perhaps TV and radio, but that's not to say that they aren't likely to make a similar choice to Twitter, if it is generally agreed upon that Trump's message is bad and either shouldn't be seen or shouldn't be engaged with. Since they have similar financial incentives, it's not totally unreasonable to think that these mainstream platforms would follow suit if Trump decided to abandon Twitter and start posting solely on one of these alternatives. Whether or not you agree with Alex Jones, he was banned from all these platforms in coordination. It's absolutely possible that the dominoes would fall, and non-mainstream alternatives like Minds or Gab or Mastodon aren't necessarily viable alternatives if their audience is incredibly small.