It'll help thousands of Americans that used to be employed by said studios but were fired not because they couldn't do the job but because the greed of studio execs made them move production outside of the US, playing financial arbitrage games against the interest of the US.

Trump is trying to reverse this by making movies outside of the US, especially by US companies, more expensive. The goal here is not some statement about Hollywood but to bring movie production jobs back to US. The extras, the people who build sets, people who make food for actors etc. And jobs bring tax revenue and grow GDP, which helps every american.