Udemy is selling a dream, more so, than an education. They mostly target lower income internet natives, who have heard of coding, not enough to do anything dangerous but certainly enough to long for the good money and great perks. You are not really committed to switching up your life, but a "premium product" at 90% off down to 20$, how could you not give it a try? It's an affordable dream and makes for an easy sale.
Seems to me they're increasingly targeting businesses, with their Udemy for Business offering that is a subscription service. I have a course published there and currently get about half of the revenue from the Udemy for Business share.
The TechCrunch article also mentions this: "It also has, in more recent years, expanded to enterprise services, where Udemy works with companies like Adidas, General Mills, Toyota, Wipro, Pinterest and Lyft and others — 5,000 in all — to develop and administer subscription-based professional development courses."