They maybe wanted to cash out their bankroll, to use for something else or just take as profit.
Or they hope the popularity that this model has given to sites like just-dice will boost their site similarly.
I am kind of suprised by their low profit in general though, especially in 2013 when competition wasn't so obnoxiously present. They had a roulette I think a month or 2 before us, and at that time there were only 2 provably fair roulettes.
If I compare their numbers with SatoshiBet, all I can conclude is that there is an awful lot of untapped potential for playt.in. Not sure if it will ever get tapped, that's up to them.
Note; I do not want to endorse this site and its shares. Do your own due diligence. One red flag to me is that the playt.in account which used to be very active, hasn't posted for ages; https://bitcointalksearch.org/user/playtin-81588