According to a comment on the article the lack of support for these registers meant the 8085 did not have a "jump if greater than" opcode. That seems like something of an inconvenience for a chip that a lot of people are going to be writing assembler on.
Comparisons between unsigned bytes can be done natively with JC, JNC and JZ, JNZ instructions. Things are more complicated with signed comparisons as there is no overflow flag. It is possible but requires more instructions.
Interestingly, while the 8086 and '186 had all the different jump instructions for signed and unsigned comparison, its microcode was limited to an 8080-like set of carry/zero flag tests. This made the BOUND instruction quite complicated and inefficient.
