But what I don't understand is experienced developers arguing about the correct capitalisation of their language's name.

I don't give a monkey's how it is written. I tend to use "Perl" at the begining of a sentence and "perl" otherwise unless I am specifically trying to distinguish between the language and the executable.

it might make them look less like newbies.

What's the point in that? There is no shame in being a newbie -- everyone was one once. And attempting to conceal that just makes for greater frustration when responses are aimed at over their heads because of the assumption they are not total beginners.

Most newbies will rapidly pick up on the clues they see in other peoples usage. Beating them over the head with it when they are just trying to get started will just drive them away.