See, I always find this kind of comment to be really weird. I think Hardstyle is cool for what it is, but what does it even mean when someone says "Hardstyle is easy/hard to make"? I hear comments thrown around like this in a lot of EDM genres.
The article quotes On the stream, the Mau5 had some struggles. He was under the eyes of a good majority of professional hardstyle producers who were watching him make classic rookie mistakes in producing the genre. That implies you have to obey certain rules to create music in that medium and there are walls you have to stay in like, "hey here's how you HAVE to make hardstyle, this is how it is done, period". If we want to get technical, hardstyle uses a lot of factually incorrect audio engineering techniques because many sounds are distorted to all hell. But that's the art of it, it works so people do it. My point is that's so weird to me that people have created rules about it, you would never hear that outside of EDM, especially considering the art of hardstyle is fundamentally breaking rules. You don't hear someone talking about hip hop or alt rock like that because it comes in so many varieties and flavors. I understand that Hardstyle has a very specific sound to it, but it's weird that people have created these rules and implications. It's music, do whatever the fuck you want and if it sounds good, thumbs up.
To be clear this is more so an observation on EDM in general than hardstyle specifically. One of my favorite recent quotes is by hans Zimmer - "if there's a rule, break it"