For far too long (e.g. in the first half of the 20th century) everybody simply accepted lots of 'rules' just because 'that's the way that things are done'. At last, in the 1960s, people finally started asking the question "Why?".
For example, people started thinking "I know that the 'right' way (according to 'convention') to use my fork is with the tines pointing downwards, but why can't I use it the other way up to eat peas?".
At the same time, schools (thankfully) started encouraging young people to CHALLENGE rules and conventions (by asking that all-important question 'Why?).
As a result, a lot of 'rules' have largely been forgotten about. (I couldn't care less if someone uses their fork the 'wrong' way up, or if they sit with their elbows on the table).
Inevitably, the challenging of 'rules' and 'conventions' has resulted in divisions between those who wish to retain such rules and conventions, and those who decide to ignore them.
Some extremely intelligent people (e.g. Stephen Fry) can see nothing wrong with the use of '4 letter words'. (I tend to agree but I still hope that people are aware of the conventions against such use, so that, for example, they can conduct themselves properly in job interviews). Others. however, see the increasing use of those words as 'a lowering of standards'.
My own frustration is not with people who DECIDE not to adhere to accepted rules with regard to spelling, speaking, etc. What worries me is when they don't even KNOW what the accepted conventions are. (If they don't even know the 'rules', how can they possibly CHOOSE whether to adhere to them or not?).