Interesting question.. I fly the A320 at the moment, and can see your point, but there are a few considerations. If the forecast conditions at the field are acceptable to make a CAT I approach (a normal ILS which is hand flown, or with autopilot down to no later than 80') we may make the approach down to minimums for that CAT I approach, i.e. not lower than 200'.
If low vis procedures are not in force, the ILS is not protected, which means backup power supplies for it and the runway lights etc are not online. Also the CAT II/III holding points will not be used, so the ILS radiating area is also not protected from other aircraft or vehicles that may be taxiing/moving near the runway.
If, before we get to the FAF the weather report given by ATIS or by the tower (or from other aircraft) is good enough, we'll carry on with the CAT I approach. If the weather deteriorates after we have passed the FAF, we can legally continue down to minimums, and land if we become visual. If not, we'd go around, hold if necessary, then either make a CAT II/III approach (which takes time for the airport to sort out), maybe needing to divert. Had to do this last week, ended up going elsewhere as the ILS was off the air.
high-flyer