(Not claiming that this particular company has a lot of profits, the question is more meant to be general. lets take rovio as an example maybe)
To take this way past reasonable, consider Instagram. If they could convince someone to give them 250 Million for 25% of their company instead of selling the entire company, that would be huge FU money and they could keep running their company, while evening maintaining a majority stake. I could see that as a very tempting option.
Also, it allows the founders to diversify a bit. Consider that these people are multi-millionaires on paper, you wouldn't generally recommend they put all of their money into one investment, even if it is their own company.
Obviously a $10MM investment does not equate to a $10MM deposit in the founder's personal bank account, but at what point is the founder no longer expected to live on Ramen?