Sorry, but that's the only bit of your post I can agree with. Have you any idea of the estimated cost (to the nearest Billion €)? Then what about a shot at the estimation of the benefits. Remember that there are other public projects competing for funds.
It seems that we have too much advocacy for projects which are of relatively low priority (e.g. Tuam-Claremorris?) or which are incredibly vague and costly. What need to be looked at are projects which address specific constraints such as 3 or 4 tracks from Connolly to Clongriffin or Malahide, or even large projects which have been relatively well-researched but then scandalously neglected, such as Dart Underground.
Never mind that simple and cheap projects such as a second platform at Enfield remain just as a set of plans after nearly a decade!