Capital gains was taxed as income in the late 1980's, but the tax was repealed by George Bush Sr.
What makes you think you deserve a penny of what an old man gets for selling his house? Or his stocks for that matter?
What is the difference between money made from your investments and money made from your sweat?
Not a whole lot. One you got in exchange for labor, the other you got in exchange for putting it at risk. I wonder if the same people who want to cap what you can make from investments would also accept a floor below which you can't lose any more money?