I think N&W kept EL and D&H at arms length. The west end of EL was redundant with the NKP and Wabash lines. The east was saturated. Why would N&W want to go where PC held most everything, and had better lines. The cost of business is high in the east too. Add in the taxes, and commuter losses, and no one with half a brain would go there.
As I said, once Conrail came, the D&H could have been a good bargaining chip for N&W against Conrail. CR still held the cards, as they controlled the routes connecting N&W to D&H. With this said, Walter Rich found a way to beat Conrail, as I said before.
I like EL. It may have been able to be pared down to a lean bridge route, needing little modification for stacks and pigs. Conrail had a much better route in the NYC route. EL was still 4 out of 4 in the Chicago New York business. No matter how we dissect this, there were too many routes serving a dying traffic base. In 2014, with increases in intermodal, and unit trains, the capacity may be welcome. Things were in dire straits in 1976.
I don't think the Southern Tier is going anywhere. It is quicker to New England, and parallels the Central. It avoids the southerly leg of going via Pittsburgh, and Harrisburg. The NS has done well with it. It will never match what CSX has in the old Central, but it does give them a direct line to Boston and eastern Canada.