[corty]

Having them wasn't a hindrance, luckily for intel. But using them to the full extent was far slower than not. E.g. call gates as a syscall mechanism have a far higher overhead compared to int80. Segments, when used in the intended finer-than-page granularity are also too slow, because changing a segment register often is very costly in terms of cache and TLB flush. That's why everyone just used a few fixed segments that almost never changed and did the interesting stuff with page-based memory management.