"Could customers please switch off there mobile phones"

On a discussion board forum for a module I did last year on language and online learning, there was a lot of agreement that the notice could customers please switch off there mobile phones was irritating. What might this irritation tell about posters' attitudes to language?

What we have is an instance of someone mistakenly using the pronoun ‘there’ instead of the possessive adjective ‘their’. Pierre Bourdieu would argue that ‘their’ being the correct word to use in this context is entirely arbitrary. There’s no reason why it couldn’t be spelt ‘there’. Plenty of other words, after all, have the same spellings but different meanings. Academics and institutions, over time, have formalised and codified language - defining ‘correct’ and ‘incorrect’ usage, e.g. “could customers please switch off their mobile phones” is correct but “could customers please switch off there mobile phones” is incorrect.

Bourdieu argues that definitions of ‘good’ and ‘bad’ use of language (spelling, puncuation, vocabulary etc.) are, in fact, manifestations of the power of those who sustain their social distinction through language. Knowing the difference between ‘there’ and ‘their’ is a form of “linguistic capital”; I can use this in my social exchanges to produce what Bourdieu calls “a profit of distinction” (aka “I am better than you”).