Cristopher,
The '51 is an EMBEDDED MICROCONTROLLER, not a Java, Linux, "whatever you want" machine. The '51 is the right choice for many control applications, it is NOT a general purpose computer. We see the people approaching problems from the viewpoint of picking some OS or language and then seeing $1 '51 derivatives popping this question every time "can I make a PC from the $1 chip". Of course it is never formulated that way, but be realistic: The '51 is an excellent choice for single thread control and measurement applications and a few more things, it is NOT a $1 PC.

Have fun, but be realistic

Erik