It's been so long coming that people probably believe the recovery is occurring in spite of Obama, not because of him.
Or, they're just not feeling the so-called "recovery." Despite all the recent employment "growth" data, labor force participation has shown no improvement, while the number of full-time jobs declined by 523,000. Most of the jobs that were created were low-wage and/or part-time, so it isn't surprising that this "recovery" hasn't translated into great approval ratings for Obama.
It's worth noting that while the current unemployment rate is 6.2 (http://www.huffingtonpost.com/tag/unemployment-rate-june/
), including people who would like a job but haven't looked for one recently due to discouragement (which are not included in the unemployment rate) raises the rate to 9.6% (http://seekingalpha.com/article/2299505-the-real-real-unemployment-rate-for-june-2014-9_6-percent
), and adding in those employed part-time for economic reasons only gets it up to 12.1% (often referred to as underemployment) (http://www.bls.gov/news.release/pdf/empsit.pdf
(page 27, U-6)).
Granted, this number was significantly worse back in '10 and '11, but it is still too high - it was at 7.9% in Jan. 2008, just as the recession was beginning (it peaked at around 17% in 2011) (http://www.bls.gov/news.release/pdf/empsit.pdf
Even though most people don't know what the underemployment rate is, that doesn't change the fact that 12% of the country is experiencing some level of unemployment (the rate is even higher in some states) that they were told they wouldn't be experiencing six years into Obama's presidency (Obama's 2008 promise of a speedy recovery in which un/underemployment would not significantly raise from where they were in Jan. 2009 has not been forgotten by most), and that's what people are witnessing in their cities, families, and neighborhoods - people giving up, people settling for part-time work - and (since we are so far in Obama's presidency) people view it as 'Sure, it's a slow recovery, but it's really helping yet and won't be soon' or 'Sure it's a very slow recovery, but it would have happened without Obama' or even 'bah, it's too slow to even be called a recovery'. Take it all into account, and it's easy to see why Obama's approval ratings haven't skyrocketed.