With the new baggage services at some not-always-staffed stations, it seems as though maybe baggage alone isn't a reason to have a station staffed seven days a week.
However, it seems a bigger limitation is that, if true, Amtrak has to hire a lot of full-time employees to do jobs that would probably only warrant part-time status. As an example, it would make sense to hire baggage handlers on as part-time employees at stations with only one or two trains a day. (It seems surprising to me that they can't do so...a baggage handler only really needs to be there around train arrival and departure time.)
And while yes, we do need more trains, saying "the problem isn't the staffing, it's not enough trains" is missing the point. Yes, a city like Houston or Minneapolis should have enough trains each day to easily necessitate full-time staff and then some. But currently they don't, and until they do it's nearly pointless to staff them like those trains are there. Especially in the day where more and more people are working online, it makes sense to invest the money in beefing up online services, perhaps at the loss of some in-person services (after all, Amtrak doesn't have anywhere near an infinite amount of money.) Hopefully Amtrak, should they do this, uses a scalpel for cutting station services and staffing, not a hatchet.