On the argument for or against ILS.
Sure the GLS is the future, or even the LPV, once there's SBAS coverage, until then LNAV/VNAV or LNAV..... why don't you have SBAS coverage?
But considering the cost of an ILS, versus changing every single aircraft already out there to fly LPV, there's still very much an economic benefit in setting up an ILS.