The x86 architecture dates from the design of the 8008 microprocessor and relatives. These CPUs were designed in a time when memory was slow and if you could do it on the CPU die, it was often a lot faster. However, CPU die-space was also expensive. These two reasons are why there are only a small number of registers that tend to have special purposes, and a complicated instruction set with all sorts of gotchas and limitations.
Other processors from the same era (e.g. the 6502 family) also have similar limitations and quirks. Interestingly, both the 8008 series and the 6502 series were intended as embedded controllers. Even back then, embedded controllers were expected to be programmed in assembler and in many ways catered to the assembly programmer rather than the compiler writer. (Look at the VAX chip for what happens when you cater to the compiler write.) The designers didn't expect them to become general purpose computing platforms; that's what things like the predecessors of the POWER archicture were for. The Home Computer revolution changed that, of course.
