Not to mention, the vast majority of people don’t need 10GbE. Most users use WiFi and never touch Ethernet. Adding the functionality would just drive up the cost unnecessarily.
Agreed, stings that they don't include 2.5G. Even a single spinning disk easily saturates GigE, getting 2.5x that without the price overhead of 10G is a pretty decent value. Even $200 firewall widgets often include 4x2.5G.
Well yes, it's the most reasonably priced upgrade. But when you start upgrading the other options and you come into expensive computer territory it becomes another thing that you need to drop cash on when it feels like it should be default at this price. Many NAS have 2.5G or 5G interface now, so it's not like there is no use case at all...
I would like to see 2.5GbE - that's getting pretty common on AMD/Intel machines now too. But afaik Apple love using Broadcom for 1G NICs, and I'm not sure they have a 2.5GbE chipset?