That argument doesn't seem to be supported.
The article points out that high school graduates are more satisfied than dropouts. Also up to a point higher income (correlated with higher education) leads to higher satisfaction. A quick google search seems to confirm that education is correlated with life satisfaction [1,2,3].
Furthermore the study mentioned in the article is specifically looking at location differences. They acknowledge that other factors like "income, education level, age, and marital status" matter more, but that there even controlling for those factors there are still differences based on location.
[1] http://economix.blogs.nytimes.com/2010/02/18/does-education-...
[2] http://money.usnews.com/money/personal-finance/articles/2012...
[3] http://www.rasmussen.edu/student-life/blogs/main/does-educat...
imagine philadelphia county which has some of very highly educated areas such as around the University of Pennsylvania. But the overall education of Philadelphia is quite poor.
im just saying that any attempt to link education with happiness data at the county level is somewhat useless for most of the country.