Although I agree in principle with the notion that people don't pay attention, the announcements about units and their destinations can sometimes assume too much knowledge on the part of the passenger.
On one station, for example, the announcer said that the train at the South end of the platform was for X and the train at the North end for somewhere else - but not all of us know our North from our South, especially on stations where the alignment is not obvious.
Passengers do not always know whether they are in the front or the rear set - they might not even know how to recognise where a set starts and finishes. What's the difference between a 'carriage', a 'set', a 'unit', a 'portion', or a 'train'? Rail-knowledgeable people go by the position of cabs and set numbers and know things like the fact that 185s are 3-car sets, but most passengers won't know it. On the three car 158s there is a cab in the centre car just to confuse matters further.
Arriving at Shrewsbury from Birmingham there is usually a very thorough announcement about the Aberystwyth train splitting at Machynlleth but it gets very confusing because the conductor has to make the announcement before the train has reversed and so the front unit becomes the rear unit and vice versa.
Sometimes the announcements are too quiet as well. Some conductors give a good clear message but on many an occasion the announcement is only very slightly louder than the ambient noise. It can be hard to tell that there is an announcement, let alone hear it clearly enough to understand it and take action. I think also that there are many folk who think that the announcement 'won't be for me'!
I reckon the only way to solve the problem is to have someone physically walk down the train before a split takes place and tell people that their bit of the train is for 'X'. That would work for short units like 158s but I don't know how sensible it would be in 8 car sets.
Apart from the opening sentence (I speak as an over-cautious to the point of obsessive attention-payer) this post sums up exactly how your average passenger often feels, when trying to establish where they should be waiting or boarding.
Please cut us some slack, we don't do this for a living you know. Typical example - Chester recently for some reason at least twice to my knowledge showed Platform 1 for the 11.35 Euston service, which was actually in and waiting on Platform 3A. Many people wandering around like headless chickens not sure whether to get on it or not - after all "the board says...".
At Crewe on Monday there was a lot of confusion as the 10.40(?) Holyhead was late arriving on Platform 11, and those of us waiting for the 10.57 to Liverpool were starting to get anxious as the time crept towards OUR departure slot and there was still a muddle going on as passengers on the eventually arrived Holyhead got out of one end to get into the other, as the train was splitting.
I was anxiously awaiting a platform change announcement for the Liverpool, but it did come in (also late!) on 11. Was it late because it was waiting for the previous train to clear? Anyway it didn't make the time up, so I only had 7 mins at Liverpool South Parkway instead of the scheduled 9, which was a helluva rush as I needed to pop into the loo en route to the furthest end of the station to catch my Southport connection, which I had to make due to timed arrangements in Southport!
Incidentally they announced on the LM to Liverpool that only one toilet was working on the whole train, which is why I didn't bother to go and search for it! Not very good is it?
The tannoy system at Moorfields is abysmal, and always seems to coincide with another train coming through, thus drowning out the announcement, which is garbled at the best of times. I blame the equipment not the announcer - it desperately needs improving.