If you honestly believe this, it makes me suspect everything else you said.
Well, tough, because it's true. Railroads were suffering from ever increasing property taxes, and the only way they could deal with them was by getting rid of as much property as possible, undermining their network effects. And like I said, it's in part one of the reasons, not the whole reason.
Interestingly most of the reasons you give are not real reasons - the Interstate system being a partial exception (though if that had been it I think the railroads would have survived), but the major ones are:
- Aforementioned tax burdens where taxes were in proportion to area and people served, not income.
- Stifling Federal bureaucracy, making it impossible to reorganize services as population shifts occurred and making cutting routes actually preferable to reorganizations.
- Aforementioned Federal bureaucracy preventing railroads from setting competitive prices. They were forced to sell many services at a loss, even when there was no reason to believe customers weren't perfectly prepared to pay proper commercial rates.
- Zoning reforms that made car ownership mandatory for anyone living in any area developed since the 1940s, plus the (deliberate, in my view) mal-administration of urban centers.
Add union intransigence to the mix, and the occasional mismanagement (Penn Central - if only they'd have let Al Perlman do his job), New Haven, etc) and it was a recipe for disaster.