meihuak Okay, so it's the composer installation process.
I understand this is unfamiliar to many newcomers, and can be intimidating. This is why we strive to be rather supportive of our community, both by providing updated documentation and active support. We'd be happy to help anyone get through the process to install Flarum, so long as they're willing to put a little effort into learning.
We think composer is the right method for us at the moment. Flarum is still in beta, which means that its code is still in a state of flux, so composer allows Flarum's developers, both core developers and extension developers, to target a moving platform much easier than by using a traditional web install method. It also takes the pressure off of Flarum to ensure that a server can support it, composer handles all the system requirement checks, so Flarum can do what it does best.
Compare Flarum's installation method to its modern competitors in Discourse and NodeBB, and I think you'll find that composer is far easier to grasp and use than the methods other use. Yes, it's a departure from how things used to be, but we're confident that composer is simple enough to understand, and used broadly enough to be reliable, to continue using it.
The future may bring something different, but right now we stand behind our decision to use composer.