Pilot reported the ASOS at MRF Airport is constantly out of service or partially functional; and inaccurate on many occasions. When the ASOS malfunctioning; ZAB Center is unable to issue the approach.

Narrative

The ASOS at this airport is constantly out of service or partially functional - or not reporting the weather online. This poses an aviation safety hazard as one cannot monitor the destination weather while enroute.As has happened before; I approached destination not knowing the ceiling and visibility until 5 minutes away when I was able to hear the one-minute weather radio broadcast. The ground visibility was as low as 1/4 SM in the previous hour; as reported by a local pilot to me later. An unprepared pilot may not be ready for this and could turn a changing-weather accident into a fuel exhaustion accident in this remote area where alternates are not handy.The in-flight visibility on my arrival turned out to be 4 SM (the GPS distance) despite the ASOS reporting 10 SM - so it is not even accurate. Local pilots report the wind direction often to be 30° 'off' - as it was tonight. Both of these are also longstanding; unaddressed safety hazards.Center was unable to issue the approach because the ASOS is not reporting T/DP/AltSet. None of the approaches allow the use of the nearby ASOS; E38. Providing higher minimums on at least one approach; using E38 altimeter setting would help. This is commonly done at other airports.All pilots here understand that the ASOS will fail from time to time. Our issue is the length of time the outage exists. Right now the NOTAM states out of service" two full months and it is suggested that it was out before that; and may go beyond two months.I have reported this issue before with no resolution. I believe it to be a significant enough issue to request assistance via this ASRS. The FAA/TxDOT should either repair this ASOS system; or provide funding so local authorities can repair it in a prompt manner.In my opinion the excuse of our distance from repair personnel is not acceptable. A larger airport would not tolerate such lengthy and repeated outages."