The fact that call gates does not disable interrupts is usually the desired behavior. Linux (and NT for 32 bit code) does not use call gates because they are not that useful for OSes that target the Unix/C flat memory model. You can probably use call gates to implement particularly fast IPC mechanism with semantics similar to QNX's message passing. But probably only real users of call gates are DOS extenders and 32 bit windows for 32/16b thunking (which is to large extent the same use case of mixing 32/16b code in single process).