The English Language Usage website says that 'with' and 'of' are alternative prepositions in the phrases 'bored with and 'bored of' and are equally acceptable but points out that the first usage is customary and deemed more acceptable.
However, there are common usages which are more problematic such as the American usage of 'different than' and the home grown 'different to' instead of 'different from'. One would not say 'differs than' or 'differs to' but always 'differs from' which gives a hint as to the more corrects usage in this case.
Of course language is dynamic and one welcomes this. The ingenuity and freshness of the demotic always adds verve to the established lexicon. However, in terms of keeping sense and of precision in language some adherence to the rules of grammar and even to usage are necessary. For instance, the use of 'disinterested' instead of 'uninterested' is to be avoided as they mean quite distinct things. 'Uninterested' means 'not interested' while 'disinterested' means 'not having a personal interest or concern in an issue' so that 'disinterested' becomes a useful synonym for 'objective' or 'unbiased'.
Language is a brain surgeon's scalpel dissecting nuance - not a bludgeon.
I often think that those who think matters of grammar and usage don't matter are those who wield language like a bludgeon. One wouldn't expect as informed a reply on matters of music from someone who doesn't play an instrument as from a concert pianist.
Those who dismiss the subtleties of language, grammar and usage know not of what they speak.