With the last version, Apple specifically advertised the "Twist Off" accessibility:
Add memory with a twist.
Mac mini comes with 4GB of fast 1600MHz DDR3 memory. And thanks to a removable bottom panel, its easy to add more. Just give it a twist, and youre in. Pop your new memory into the SO-DIMM slot, and youre out. Or you can configure your Mac mini with up to 16GB of memory from the start at the Apple Online Store.
Apple used to advertise how accessible their machines were (the G3, G4, and G5 towers in particular). It's one thing to make a machine more closed off, such as the portables, if it allows more room for a bigger battery or a thinner machine, but has anyone ever complained that a Mac mini was too big or too expandable?