Sometimes I get OCD with my bracing. I completely understand why someone would ask the question about the braces as well. I've just been around so many boxes over time. Part of designing is instincts. Sounds is alive. You gotta treat sound like it's alive, sometimes sound does things that don't always make sense at a first glance. So when I design, I just put in every fail safe I think is needed, whether it's obsessive or unnecessary or whatever. I'm over designing a box; you aren't going to get my box and have it fall apart any time soon, as long as it's built decently. Not everyone has the same tools. I've ultimately got a CNC machine at my disposal. We get cuts very very close to what's intended. Some people don't even have a table saw or a circular saw with a guide. Idk if accuracy to you is 1/4" tolerance or .001" of tolerance. So I design my enclosures to work under a lot of different circumstances, when it comes to how people wind up building their enclosures.
I started building boxes with NO TOOLS and designing them during class in high school. I know what it's like, so it doesn't bother me when I have to design for a "noob" who's box looks like a kindergarten project. I don't care, everybody has to start somewhere. I'm gonna design it so that even if you make mistakes, the design will still be likely to hold itself together and perform. That's just the mind state I have while designing.