Mahmood.....to dislike PNP transistors for the reason you state is kind of silly.

You will notice that I always use a pair of resistors on the base connection of a transistor being used in a switching application. If you have some trouble with the high level of the 8051 output just calculate a different ratio of the base series resistor versus the base to emitter resistor.

Your concern is certainly much of an issue if, as is common practice with many engineers, the base to emitter resistors are left out of circuit.

Michael Karas