This was writte 2 days ago, so excuse my being late, but here we have fundamental DISagreement!
NO, not "nobody" is taking Trump's tweet seriously, nor are they MEANT to not be taken seriously. They are meant to be taken seriously by very large numbers of Americans, and tens of millions do take them seriously - agreed?
However, your post implies that Trump's tweets are, as a rule, not true, not fair, not good, or lack any other quality that frustrates their being taken seriously. I agree with you on that!
So why does the POTUS take valuable time out of his tight daily schedule to tweet stuff that sane, rational people oughtn't take seriously?
-> Because he consciously, with focus, seeks to activate the insane, irrational among Americans into his employ.
That cannot be a good thing, nor should it be ignored or downplayed. This is the very core, the stand-out characteristic of the Trump presidency: that it goes out if its way to seek, find and use the very WORST of America.
It's really simple: any acceptable President would not tweet day in day out things - hateful, petty, small, nasty things - that nobody ought to take seriously.