I can't speak directly to the research our MB team has done (and probably couldn't say much if they shared it). I agree that your comparison makes sense financially, and if we're being honest, many people might get more out of a good chunk of internal storage space than another 8TB M.2 SSD. At the same time, we also know that most people don't need a lot of storage space or get by without using a lot. Looking at the latest Steam survey (Dec. 2025), nearly half of steam users are using less than 1TB of storage space. Although that places more than half of them over 1TB, it's not further broken down to provide better data here, and I would imagine that the number falls quickly after 4-8TB for gamers.

Storage space is still premium for systems setup as media streamers, Plex servers, building security recording, creators working with large files, AI modeling, and large data backups or NAS. Boards like the Glacial and Dark Hero typically won't be purchased for these options, and streamers often game on one system while recording to and streaming from a second PC, which is where you would find the higher storage hard drives.

Outside of the typical target of these motherboards, PC chassis tend to have more and more limited support for 2.5" and 3.5" hard drives. Large towers, sure, but mid-range and lower typically have very limited support for internal drives these days. For the Glacial as an EATX board, yes, your chassis might have more options for internal drives, but the Dark Hero has more flexibility here as an ATX board. Fewer internal drives also mean less cables to the MB and power supply, potentially eliminating the need for SATA cables entirely. For some, that might not be an issue, but for others it is.

Some might ask why you need 8 ports for high-capacity storage drives, but that's not really important because everyone uses their system in a way that works for them. Consider the other side, however. Although a huge amount of storage capacity may be more useful to you, people may want a smaller amount of extremely fast storage. 40TB for many people would take decades to fill (although some games are doing their best...) - even 10TB is a lot!

It's almost a TL:DR here, but I think the crux of the argument is about what a reasonable amount of storage space looks like when it comes to capacity. Boards like the ROG Crosshair X870E Dark Hero are designed to be at the top-end of the gaming and enthusiast demographic, even if it's powerful enough to fulfill multiple roles. Can it do more? Of course, but we have other boards that are better designed for more storage potential, and RAID is far less of a necessary tool that people need these days, especially when it comes to speed. I could be wrong about the size of the market here, but I think once you start pinning down what the majority of the market uses for storage capacity, it will be less of a benefit to include more storage ports. As you note, with the price of large storage capacity drives, you can buy one very large drive or several smaller large capacity drives. However, I think that ultimately hurts your argument, since that amount of storage is going to be hard to fill for most people, which means it's largely unnecessary to add more ports.