I think that's a bit naive to think that's the main reason *some* guards never leave the cab.
And if they really are scared of the public, so much so that they never walk through the train then they're clearly unsuited for any public facing role.
*most*
Okay, maybe not scared, lazy then.
A lot of people should not be in public facing roles but they are, many people take jobs for the sake of a job and if they can find ways of doing least amount of work possible, they will. And what better way of doing that than sitting in the cab of a train only poking your head out to ensure peoples legs aren't trapped in doors.
It makes a mockery of the 'trains need guards' argument and when other train operators happily run up and down lines with no guards, it further proves that point.
Are you talking specifically about SWR here or in general?
Last time I went on SWR was several years ago, but my much more recent experience of Northern, CrossCountry, London Northwestern and Great Western, as well as TransPennine on the occasion that they manage to run a train, has been that guards are more often than not present in the passenger compartment.
Long distance trains, ie Cross Country, GWR and EMR have guards and yes, you have visuals on them but that's only because they are checking for tickets or to buy tickets.
My main issue is the short distance routes need for a guard if they are just going to lock themselves away out of sight, ie, to Hampton Court or the Kingston Loop services. Travel can be dangerous at times for vulnerable people so if you're going to have guards, be seen so it deters these unruly youths running around trains and terrorising people.