Well for a kick off, from the ATIS I'd have known the cloud base. If the cloud layer I was inadvertently flying through, whilst on the glide slope or above it, was only going to be 100 ft thick I'd have continued to a pragmatic point. I'd also advise ATC we went IMC and we are following the glide - id be extremely surprised if ATC ( even in BCN) weren't accomodating - especially since they seem all to aware of the weather situation. I certainly wouldnt do what these guys did and I can say that without the benefit of hindsight. I'm not blaming but it wasn't sensible in my opinion.