Some people take 10 years to finish their PhD, centurion. You either have a PhD, MD, etc...or don't. Yes or no. Do or don't. I know this, and I am not a PhD or MD.
And once you are awarded your PhD, it's not like you are automatically credible or anything. In fact, I wouldn't even suggest bringing fresh out of graduate school post docs on board either.
Your success in the field of science is determined by much more than a piece of paper or where you went to school. My brother went to Cornell as an undergraduate and majored the field of biology; he then went to UC Davis to earn his PhD; and some might consider UC Davis a second tier institution. However, immediately after earning his PhD, he went back to work at Cornell as a post doc to earn basically nothing in a Postdoctoral Fellowship; I don't know if you are aware, but fresh out of grad school post Docs really don't have any credibility either. My brother worked his ass off for his boss and wrote up a proposal and in about 9 months was able to get his lab a grant for about $109,000 from the USDA. A few months later, he was offered a job at Harvard -- and he STILL doesn't have his own lab yet. He is still a post Doc. So it's not like you just go to school for a few years and "earn" instant credibility with a PhD.
You go to school, get your PhD by working your ass off in your field of choice, then get your PhD. Then, after you get your PhD, you earn basically nothing until you are able to find a creative way to earn money for the individual you are working under, and he or she takes all the glory (well, mostly). Then, after you finish several years of work, (maybe 3-10 years), you are given a real position at a major research institution (hopefully with your own lab) and you manage other post docs, etc. and the cycle continues...
I was trying to be generous to anyone who has even earned a PhD. Just earning a PhD doesn't make you automatically credible in the field of science either. It takes a lot more than that.