I think it’s more about getting “real world experience”. Obviously, if you’ve got a “real” job offer, then take it. But for many of us, the chance to work on real projects, get some references, and build our portfolio is a good one. I don’t think future employers are going to look down on it because it was for an NPO. I think they’re going to be more interested in the work that you did and what you learned from it. I think doing an NPO project is more productive than waiting around for a company willing to hire someone with just some fCC certificates and good intentions as credentials.
Any company or individual who would devalue a non-profit portfolio compared to paid work is a place where I would not want to work.
As an interviewer, I actually like to see volunteer work on a candidate’s LinkedIn profile or resume, and feel like that type of effort contributes the culture in the workplace in many ways.