No. It’s a perfectly valid complaint, just pointed in the wrong direction perhaps.

About Cinammon: it isn’t customizable because that isn’t really why it exists. Its purpose is to have a lightweight, evocative-of-Windows desktop environment.

If you’d like a heavily customizable DE, the default choice is (KDE) Plasma. You can install it on Mint without a problem. There are plenty of guides, and this one seems a bit more concise than the other few I’ve checked.

My recommendation if you do check it out, however, is to use the “desktop” package (as opposed to the guide’s “standard”). You’ll just be missing out on KDE apps such as their text editor, but you already have one that works, and you can always install it manually.

Cinnamon is made by the Mint devs for Mint the distro. Plasma is made as a uber-featured DE for anyone. Which doesn’t make Plasma any better, it’s just that their goals are different.

Cinnamon values simplicity and low resource use, while plasma prefers complexity and customizability (which causes a bit of bloat).