The OP described 300 square foot units with a bedroom, bathroom, kitchen and living are, surrounding a shared living area with additional amenities. So, each resident would have their own private space.
This is actually more than some families (2 parents plus 1 or 2 kids - or 1 parent plus 2 or 3 kids) are able to afford.
Looking at the floor plan in TFA, the individual units are similar to some 2 room suites I've been in in hotels - except the hotel suites lacked a kitchen (having only a microwave and a minifridge under the TV in the "living room" part of the suite). The kitchen and bath are tiny. The "open" layout of the kitchen makes it less cramped than the space it occupies otherwise would be, However, the shower stall in the bath looks like it might be too small for 2 people to shower together.
For single people not yet ready to consider having a live-in romantic partner, I think it could work.
As a point of comparison, my girlfriend and I lived in a 400 square foot apartment for 2 years after we graduated from university. As it was more space then we had in the university residence hall, we were comfortable. At the time, our main reason for looking for a bigger place was so we could have a child. We quickly discovered we could buy a 1200 square foot house (plus basement, giving us a total of 1800 square feet) for about the same total monthly cost as renting the apartment.