This literally does allow anyone to make a theme though. You don't even need to know the hex values for the colors you want to use, because it provides a built-in color picker that will populate the fields for you. This tool allows literally anyone to simply press a few buttons and it will generate all the CSS code for a theme.
Getting into subjective territory here, but most of the themes on-site are already not good. I can't imagine reducing the work needed to create a theme to "press five buttons and upload" will somehow lead to people making good themes now. The result is almost certainly going to be a geocities-esque Web 1.0 design disaster, wherein anyone who ever thought of a color combination can make a theme without any understanding of basic design principles or accessibility concerns.
And we haven't even discussed the maintenance issues this will inevitably lead to. Every minor change to the site's structure or theme will have to be re-implemented across dozens or even hundreds of CSS themes which were made in five minutes. Do you really think that someone who just pressed a few buttons and uploaded the code that this tool spat out is going to have the knowledge, much less the inclination, to maintain their theme for what could be years? I don't! And when it breaks, it will inevitably fall to tech team to deal with the problem, and while I cannot speak for them, I highly doubt they have the manpower to maintain what could potentially be dozens of abandoned themes.
Again, this isn't a tool that just makes it easier to make themes, or helps people learn how to makes themes, this is a tool that literally makes CSS themes. I don't think y'all quite grasp the significance of what that means.