So what is it that makes it sus? You gonna start peddling the digital fentanyl are turning the kids pro-palestine Matty? Or are you going with the old reliable "the left is antisemitic"? Because you're not adding any conclusion here.
He isn't just implying that caring about causes is suspicious (well, not entirely), he is saying that caring about this specific cause this much is suspicious.
What is he suspecting lies behind it though? China, Russia or Antisemitism seem to be the most likely answers as he is a turbolib who doesn't understand why having your countrys leadership full throatedly endorsing an ongoing genocide that they're instrumental in perpetuating is a cause of outrage.
Taking into account his second tweet ("I took it very seriously, but it would be weird if some average college student was obsessed with this."), I do think he's implying that caring for any cause outside the US is weird at least (expect for professionals like himself of course)
But I also think it's all bad faith to shift focus from the current events from a natsec worshipping, PMC shitlib as he would clearly have remembered the protests against the Iraq war by a big section of the american public