So let's look at this in a lot more detail. Let us for example look at a CAT 2 approach into Stansted. We get the latest ATIS coming up to CLN and check in with Essex Radar with "Bloggs XXX a Boeing 797 with X-ray".
At this stage the conditions are within limits.
Then things start to get busy and suddenly you are on finals. While all this is going on the RVR is dropping and Essex are so bl**dy busy that they are late in handing you over to "Keep 160 to 4DME" to Stansted Tower.
They tell you on check-in that the RVR is now xxx/yyy/zzz.
This is below your minimas but since you have already passed the IAF with above minimas then you are allowed under JARs to continue to minima and land (if you can see the runway).
So, absolutely none of you Monday morning quarterbackers out there can have a go at any particular crew for you simply do not know the circumstances. You might well have recorded the ATIS at the time but that is meaningless for the ATIS is history.
For example, Essex Radar require you to check in with your aircraft type and ATIS Callsign.
I went into STN one night and my F/O did EXACTLY that. The ATIS was giving a 05 arrival and I was not too bothered when I came off ABBOT on a heading of 270° which looked like the feed-in for the downwind for 05.
Imagine my surprise when we were then told to lock on and call established! We are still at 6000 feet.
I told the man that this would put us on to a heading for downwind and was then told that the runway had just been changed to 23!!!!!!!!!
We were now rather high!!!!!!!! And fast!!!!!!!!!!
Anyway, we made it and landed safely. I complained about the unexpected runway change on taxi-in and was told that I should listen to the ATIS!
I rather lost my rag at that point and asked "them" to listen to "their" tapes and to confirm which ATIS we had confirmed on check-in with Essex Radar.
We got a grovelling and I mean a grovelling apology and so the matter went no further.
Finally, I would always advocate making an approach in marginal conditions when you have a sensible amount of fuel on board but not when you are down to minimums.