Was Hillary Clinton such a crippled, establishment candidate that voters stayed home in droves because they were so unenthusiastic about her? With all the votes now counted, here's the raw data:
The 2016 election had the third-highest turnout of the past ten elections, so there was no general lack of enthusiasm. However, the Democratic share of the turnout was a couple of points lower than usual. I don't think we have the data to know exactly what caused this, but the most likely explanation is that a small number of dedicated Sanders supporters decided to stay home rather than vote for Clinton. The Republican share of the turnout was about the same as in 2012.
Roughly speaking, there weren't any major shifts in turnout, and if you dig down into the exit poll data you won't find any big shifts in vote share by race or income or age. You'll mostly find a few small shifts (negative among young voters, people of color, and high school grads, positive among college grads, married women, and high-income voters) but only of a few points. For political professionals there are some lessons here, but in a broad, national direction sense, there's really not a lot to see.