The compressor is accelerating the air into the combustion chamber, not slowing it down when the aircraft is static, or at at slow speed. 'Inlet drag' becomes a factor at higher Mach numbers, I believe.
twochai Err, the air is considerably slowed-down in the compressor i.e. it's a convergent duct. The air is then accellerated in the diffuser (a divergent duct) and directed into the combustion chamber.