Royalistflyer, I think that's an over-simplistic assumption which doesn't account for the sheer technical difficulty of such a concept. To suggest that the USAF's decision to upgrade their F-15 fleet is proof that stealth is "pointless", is a bold leap. Stealth isn't - and has never been - a panacea. It re-baselines the lethal and survivable characteristics of air platforms in the face of newer, more clever radars and EW; radars and EW that may render non-stealthy inventories extremely vulnerable in a near-term fight.
If I have a fleet of jets with hours left to fly on them, I'd like them to be useful in conflict for their remaining life. Ergo, I upgrade them to keep that vulnerability as low as possible, in itself making them more lethal as a result; clearly I'd add direct lethality improvements as well. Agile, E-scan radars, digital EW and a bunch of other eye-watering tech can give a decent hike to an aged platform for relatively low cost, but it will never have the already-described pedigree that stealth affords.
We ignore our potential adversaries' capabilities at our own peril, but we're also very quick to criticise our own. Ultimately, that approach keeps us honest, focused and may even give false succour and confidence to our foes. It's a good thing, IMHO.