The nation's freight railroads paid good money out of their own pockets to " join " Amtrak and be rid of their privately run passenger trains back in 1971. Consider that even " Pro Passenger " lines like Santa Fe gave in, after crunching the numbers. Also consider the secondary trains that were eliminated, as well as entire railroads that went freight only, and it is easy to see the cost savings.
With regards to wages; yes Amtrak does have a lower wage structure than the freight railroads, with greater job description flexibility too. When Amtrak took over the operating crews ( Engineer / Brakeman / Conductor ), the crews that transferred usually wanted a more predictable work schedule, or were low seniority & couldn't hold a regular freight bid.
Now consider the equipment; Amtrak is in a world of hurt already with regards to availability & reliability. New equipment orders MUST be issued in the next 2 - 3 years, with delivery in 5 - 6 years, if the system is to avoid a meltdown. The recently passed funding bill will allow funds to begin this crucial process. No freight railroad has the needed know how to order passenger equipment, nor the facilities to maintain it. More ( tax ) money would have to be spent, on a duplication of effort. All in all, a non - starter I think...