I would agree that many try to earn money with it, but the crucial question is, how much do they earn per Hub and how long does it take to earn eanough money to receive a pay out?
If you look at your statistics here at Hubpages, you will see the number of Page Impressions. Multiply it with the number of ad spaces in each Hub, then you know the potential number of Ad Impressions that your articles generate. Withdraw then the 60% rotation from hubpages, then you know the amount of the potential Ad Impressions you would receive.
And if you then look into your adsense account, you will notice that the number of valid Ad impressions is much lower. I receive only about 5% of valid Ad Impressions from the total number that should be generated.
Well and if you then think that clickrates are 0,1% or even lower, then you can imagine that you would need masses of visitors only to reach the $ 50 pay out.