Doesn't make sense.... 
I agree with you, it does not make sense selling at a lost. Aside from that Bitcoin had proven itself the capability to recover. History proved it. Just look at the 2013 bubble and 2014 burst. It goes down to sub 200 but then goes on a rally for almost two years to beat its ATH. So I guess it would make sense if we decide to buy more, now that Bitcoin is <$1000.
Yeah its good time to buy more bitcoins as price is below $1k so the people who were waiting for making an investment in bitcoin at low price this is the best time for them as price may start recovering back in coming days and if they don't buy now then they will miss an golden opportunity of buying at lower price.