You have to sometimes, but hey it could be worse. We could be arguing about the colour of a seat cover or handrail....
To be fair direct rail service outwith Manchester are still very much in their infancy, but are a growing market so show that demand is there.
The thinking behind them being part of a bigger strategy is that as MIA grows it's international market, it will make connectivity to all the major towns & cities attractive enough to encourage business beyond the capital. Currently getting from the UK's major hub at Heathrow anywhere other than the capital is difficult by rail, and still very limited by air. My argument, as indeed many others is, that London could not have grown, particularly in the financial sector without the international connectivity it enjoys. So as Manchester Airport is the biggest airport outside of the Home Counties, by improving both the journey options to and from it, and improving connectivity there is a reasonable chance that this will help bolster local economies. Manchester is already enjoying some of these fruits, but the plan is not simply to put all eggs into a single basket as with London, but to try and spread it out across the region. Otherwise all will descend into Manchester every day, and heap on even more misery for it's commuters.
Now of course that's not to say it is a guarantee of sucess, indeed far from it. But it is part of a wider strategy to get the North of England on the map as it were. And let's face it, we are talking about a couple of trains an hour from Yorkshire & the North East, and from Merseyside & the North West. It really shouldn't be so difficult to enable with a bit of joined-up thinking. As for the locals, well I totally agree that they need to feel the benefits of investment, starting with longer trains (and the platforms to accommodate them) to get the capacity up to and beyond current demand. Simply declaring that Manchester routes are for Manchester people only won't solve the problem, and will probably create many more of their own, such as Ministers becoming reticent to rubber stamp improvement projects because they perceive that they will only benefit passengers for a few hours a day.