For about a year after the release of ASICS they used the average GPU efficiency and an electrical cost of $0.15 per kWh for similar charts. This lead to an underestimating of effieincy by at least a factor of 100x and lead to a more than one false news stories about how bitcoin uses $50M a day in electricity (or some equally ridiculous number). This is despite countless request from lots of people for them to fix the "stat" or just delete chart (no info is better than wrong info). They didn't for more than a year so accuracy of stats is not high of their list of thing to do.
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Am I then wildly wrong to conclude that the net profit for the entire day of mining was $11,914?
Not that it matters for the reasons above but deficit (or surplus) already implies revenue - cost. So if the deficit is -$2.4M then blockchain.info is saying miners would be losing $2.4M not $11K a day by mining if the block subsidy was zero. 
