2T oils are engineered to be mixed with fuel and burned with the fuel. Standard motor oils are mostly detergents and additives needed to stabilize the lubricating properties in the crankcase of the engine, and these additives will quickly leave deposits when burned in a 2 cycle engine.
A very old 2 cycle lawn mower I owned stated that you could use non-detergent 30W motor oil at 16:1 if 2 cycle specific oil could not be obtained. (The recommended ratio was 32:1 when using 2T oil) Man, talk about mosquito control!