Can you elaborate on why you think they suck? IMO most of the Arch derivates fill very good roles. Arch itself is a nice distro but you can never suit every user, and the derivates do things that Arch itself would never do.

Most importantly I believe there are lots of people who would have never used Arch vanilla but they get to enjoy "second hand Arch" and that's a good thing, isn't it?

My take on the most prominent Arch derivates (forgive me if I forget any, it's off the top of my head):

• Endeavour has a rapid GUI installer. It may seem like a small thing but sometimes you don't want to go through an uber-customizable multi-hour install process. It's not a beginner vs advanced thing; seasoned users can also want to save time. This installer goes against the Arch goal of providing full install customization so it will probably never be in Arch, but it is useful.
• Garuda goes one step further and offers lots of optimizations out of the box. As great as it is to have complete freedom to configure your system sometimes you want a distro to step in and do it for you.
• Manjaro goes in another direction and attempts to be "stable Arch". That may sound like a wierd thing to do with a rolling distro but it works suprisingly well. The catch is that in doing so it sacrifices a lot of what makes Arch Arch; it has a "mommy knows best" approach and tells the user to not customize their system too much. This of course is complete Arch heresy (which probably explains all the rage against it). But I think it has struck a good niche as "Arch for the lazy" – people who would like a rolling distro but are afraid of bleeding edge.