I am being practical, there is one other issue so lets explain it using a theoretical Dublin Galway HSR....one that will not be built either.
Lets say Taoiseach O Cuiv announces a Dublin-Galway HSR. We all know that such a line would be straight and in a straight line there are only 2 major towns, Mullingar and Athlone.
There is no point serving Ballinasloe or Athenry or Kinnegad with HSR, no populations. This means that the whole of East Galway and Roscommon will be up in arms looking for 'their' station on the HSR and that anyone will any sense will tell them to fcuk off with themselves and their HSR station. The whole of East Galway and Roscommon will then object with NIMBY shite erupting everywhere.
Eamon Ryan will inevitably stir the pot by advocating bicycle lanes along both sides of this HSR and being "in favour" of HSR stations in Moate, Enfield, Ballinasloe, Taughmaconnell and Athenry...with cycle racks of course. Eamon loves to indulge in this victimless whataboutery as we all know.
As well as that you will have to have 'headline' 59 minute non stop services as well as 1:15 stopping services to beat the car (now 2 hours) or the bus @ 2:30 centre to centre nowadays. A Dublin-Galway HSR has to make it in 59 minutes to justify the investment (it is ~200km)
In the context of Dublin-Cork HSR I do not see any merit in stopping anywhere in Tipperary at all but we will have to concede at least 1 station there, probably Thurles. This will have Team Lowry and the Mattie McGrath factions against as they represent different parts of Tipperary which will be traversed by the service. If you go Thurles Mallow straight you will need a short tunnel under the west side of the Galtees...possibly.
The success of
any HSR project will largely be determined by to whom, and how, you say fcuk off No!. And if you make too many concessions to populist local interests like a Team Lowry then it cannot be, by definition, a HSR. If there are more than 2 HSR stations between Mallow and Naas you have failed entirely and the money is wasted.