That's interesting. We Welsh are in quite a unique situation. You would never have people in the north of France saying that they have more in common with people across the border in Germany than with people in the south of France, and nor in most other countries for that matter.
I suppose I will have to agree to disagree, for me Wales is a country and therefore it should have railways that connect up just like any other. Now of course, there is the issue of demand and the fact that the towns up the West coast are small in population. In the 1990s, with devolution, the government had a perfect opportunity to help re-balance and 'reunify' Wales so to speak but blew it. If only the Welsh Assembly and it all the offices had been located in Aberystwyth rather than Cardiff, with the capital moving to Aberystwyth, then a) Wales would have had a capital and a Welsh Assembly situated centrally enough to unite Welshmen, north and south, and b) Wales's population would be a tad more ballanced, if only by a small degree, as Aberystwyth would naturally grow. The government had an opportunity to create a more balanced and unified Wales, but turned away. And its completely incomprehensible that Cardiff, a city that voted against Devolution, was the city that got all the institutions and status from it.
So yes, we can talk about levels of demand, or a lack of them even, but its also worth asking why that is the case, namely, why Wales is so divided and mentioning that if the right decisions had been made, Wales would not necessarily be in that situation, and the demand for north-south rail travel would be less 'unusually low'.