How do you know Delta is making money in TXL on year aound basis?? I think you underestimate the huge cost of operating a widebody. You compare the cargo revenue potential of between the two of the most busiest financial capitals of the world with the 2nd tier German cities and argue how HAM, CGN and TXL deserves a widebody. That is apples to orages.
I agree Continental does need more widebody, but to connect places like U.S-China, IAH-MAD, IAH-FRA, and upgrade South America and even explore Middle East and I will agree those places would have huge cargo revenue potential.
No matter how you slice it, Europe is seasonal, look at how everyone cuts back on flying in the winter and Delta does more than others, their TXL is about 4x a week because their inability to downgrade to smaller equipment up to this point, their risk on operating the B767 in cold winter Europe is simply higher, rather than making it work with B757s. Try running a B767 to Scotland in the winter. Delta has out of ATL and they are not coming back. Instead they will send a B757 from JFK. Continental has proven success in the market and Delta wants a piece. There you go.
Also, passenger revenue is *not* just icing on the cake, it's the coach section that's icing on the cake. Places that deserve widebody are places where it can be filled with premium revenue in BusinessFirst, and I'd bet TXL, HAM, CGN are not at the top of the list. To sum it up, although a stretch, the B757s do have a place in the European market from the U.S.