He says that movements are great, but they're necessarily harder to build. Convincing people to change the way they approach their job is _hard_, even if you're right. Then you have to sell them software, which isn't trivial.
Their competition, Marketo, didn't build a movement. They latched on to the existing trend of Marketing Automation, and they built a huge business, at least as successful as HubSpot.
In both cases, the software and ideas were new, but as a company, you don't have to be the standard-bearer for your movement. You just have to support it.
As others in this thread have argued, you don't even have to have a movement to sell software. But fundamentally, if your software doesn't enable people and companies to work differently, you haven't built something deeply valuable. Outside of the early adopter SF-product-hunt folks, nobody wants to buy new software just for kicks. People buy software to change and upgrade their workflow. You can call it a movement or a trend or a wave, but it's always about change. If you want to build something enduring or big or valuable, you need the wind at your back, bringing a useful change to your customers.