One big reason: They will build in a way out, a way to escape any of the new taxes.
Oboma refuses to touch their loopholes. He wants to tax income only. The rich liberals have their money stashed away and live off that, or use the loopholes to deduct any income they do get. They won't have to pay a penny after all this is over.
Only those with smaller businesses and paychecks will get hurt by Obomanomics. (Oboma is being very careful not to let anyone touch HIS stash!)