Well, they actually do, and that's the problem. And I say that as someone who thinks Trump is an utter arse.
For example, they're not keen on a huge influx of foreigners from a different culture. Maybe you're dismissive of that, but it's because you're not listening.
Or, for example, they want to keep their jobs, e.g. coal miners. Maybe you're dismissive of that, but it's because you're not listening.
Or, for example, they're tired of politicians saying they'll do something but then nothing actually happening. Mainly because there are downsides to that action, e.g. because mass immigration now drives growth due to falling birth rates, there are no real attempts to stop it. Maybe you're dismissive of that, but it's because you're not listening.
Look at what happened recently in most western countries and it comes across as rigged. Mass immigration even though the population opposes it, no consequences for bankers in the 2008 crash, widening wealth inequality, falling wages when you take account of inflation. And America has really weird political dynasties, Kennedys, Bushes, Clintons. It's supposed to be a democracy and yet somehow you almost have feudal-esque ruler inheritance.
You can see why Trump's anti-establishment message worked.