Why would that wipe them out? I know plenty of people with less equity than 30% who would not be wiped out by such a decline. They would continue working and pay their mortgages as they are doing now.
That's not what mine looks like. Mine has no keyboard. I press a button and a number appears, which I then enter at IB after entering my username and password.
One reason might be that trading is more of a zero sum game - minus commissions, so actually a slightly negative sum game. In investing you ride the coattails of the economy, which has a good record over the long term.