they are braindead

because if they'd solo mine they could also participate in the jackpot and win lots more quarks, the winners from Christmas are:
http://quarktalk.org/threads/mining-jackpot-winner-s.1006/ the next draw will be on 21 July 2015 so anyone wishing to get out of the pool you could be lucky and win much more

As for the attacks and destruction lol, there's nothing much any majority can do without harming itself, plus Quark has double spending protection unlike most other crypto currencies so we are protected form any form of fraud as long as you keep your private keys safe.