i mean i guess it all just depends on your perspective
for example, most of my IRL friends play on PC or some other console for the most part, and spend just as much time playing on it as I do but that doesn't necessarily mean they're losers
like someone said, actors play themselves out as other people so why should roleplaying be considered as something losers do
i think it's because it's tied to a computer, and computers are associated with games, hence the stereotype of "oh you play videogames, you're a loser", as opposed to acting, which is physical.
you could say that some nerd with no life roleplays as someone completely different than themselves for the reason of being 'socially acceptable' on said server and the fact that someone of that 'status' is doing such is what makes roleplay for losers; like a place where other 'misfits' reconvene. (just a specific example)
as another example, some people get into this type of thing at a young age, or when things like sports are available, so someone might say you're a loser for playing yourself out as another person instead of being physically active/in sports with the chance to socialize
despite them not realizing that roleplay and it's communities are a good forum for socialization
it really just comes down to your definition of loser. i mean if someone is playing sports daily/being active, but they're pretty bad at it and have decided to go with it instead of moving on, you could call them a loser
then again, you can just call it dedication
but you could also apply the same thing here in some ways
say there's someone who bounces on and off of RP, but they keep coming back for some reason
maybe it's because they're losers
or maybe it's because it's a good chance to meet new people
or maybe it's because they just get bored
maybe it's just because RP gives them the chance to be what they never could be
who knows