I wonder how many complaints of mis-selling tickets there would be given you have to be offered the cheapest ticket for your journey and not all TVMs can do that, while some of the ones that can need special notes - see the TVMs at Chester which tell Liverpool passengers after 09:30 to NOT buy a ticket to Liverpool STNs.
As ticket office staff can carry out other duties as well which TVMs can't, like taking a disabled passenger over a barrow crossing which passengers aren't permitted to use unattended, keeping the station clean and tidy or contacting BTP if a criminal offence is committed, would the RMT be happier with your alternative?
I am not saying that it is a good idea to get rid of station staff or replace ticket office staff with TVM's and Agency staff, in fact on the contrary .
But once the experiment in reducing operating costs by regrading on board staff has proven to be a failure and it has not resulted in the cost savings that the TOC expected , the next rampage for the axe wielding accountants will be station facilities . Things like toilets , ticket offices and places for commuters to park bikes or wait for the ever delayed trains are all luxuries that are not actually required to run trains . Mark my words do not think that your beloved ticket offices and stations are safe because they are far from it . Just look at the broken promises about ticket offices that have led to much upset in London .
Anyway jcollins you are yet to answer my point about the TOC's responsibilities with regards to protecting staff from assault . If every single train has to carry a second member of staff or it wont be able to run. What do you actually envisage guards will be doing on late night services out of major cities on a Friday and Saturday . I can tell you now the RMT will not lie down and accept staff being forced into performing revenue duties on these trains because that would amount to forcing people into an unsafe working environment .