The fact that they qualify it as an "online master of science" makes it significantly less attractive. It implies they're not willing to put their name & reputation behind its equivalency (in terms of rigor & qualifications of outgoing students) to an offline degree.
I'd do it in a second, but then I'm probably the target audience (other than not having completed my BS). I'm almost 40 years old, with a wife and child, and the flexibility is crucial to me. This isn't an alternative to a traditional MS program; the traditional MS just isn't even an option for me. I see it as a way to get credit for the MOOC work I'm already doing for fun and fulfillment.