If my career was based on a bunch of lies I would expect a lot worse. That's kind of my whole point. If I sold a website to somebody based on claims that it would do something it doesn't do, I would expect them to sue me for 100% of their money back plus damages, not just 8%.
And keep in mind with Lumosity, $24 mil is the revenue for 2013 that I could find, who knows what they actually made in 2014 and 2015. If we assume it was just flat that's $72 mil, which makes the $2 mil fine 2.7%.
It would be like making $100k as a developer, but using some shady quasi-legal loopholes on your taxes to save a bunch of money. Presumably you would set some aside in case it ever turned out that what you were doing was not considered proper by the IRS. My point is that the eventuality of this couldn't have come as a surprise to the company.
That is irrelevant to the question whether or not 8% of your yearly income is significant. I was only countering the opinion that that $2m is nothing to a company with a $24m yearly revenue (regardless of why it is taken away).
2/24 is 8%. How would you like to be fined 8% of your yearly salary?
Make $100k as a developer? $8k please!
Good thing I'm not blowing gently in your other ear; that would be 16 thou.