Well despite Blizzard’s initial leniency which only banned players until 2015, as opposed to a permanent ban, players continued to bot the game anyway. Blizzard has since announced that they are issuing yet another wave of bans on Hearthstone players who were caught, ultimately netting several thousand Hearthstone accounts in the process.
Assuming Blizzard kept to their word the last time, this wave of bans is expected to be a permanent one, meaning that you will need to make a brand new Hearthstone account if you wish to keep playing the game. You will also lose all your cards and progress as well. The earlier ban was apparently bad enough to the point where the developers of the bot were forced to shut down.
However it is possible that the developers simply closed shop as the alternative would be to keep operating and risk getting sued by Blizzard. Given that Blizzard has successfully gone after other bot makers, we’re sure that these developers probably didn’t want to push their luck.