[Quiet Man Cometh]

Those do sound more like rules for academic writing. Looking back I think I must have had a lot of very liberal English teachers given I've heard of some of those rules but only within certain contexts. My grade 12 teacher had us write in a number of different styles to cover basics, like descriptive, exposition, instructive (which was written in second person) persuasive, etc.

On the academic end, "but" was another word that was typically improper to start a sentence with, but that has changed over time. One of my college professors even brought it up. Same with "I." It's becoming more acceptable to make personal statements in papers because it is acknowledged that people have their own thoughts and material to add to topics in question. The paper, however, should not be flooded with them.

There are rules, and there are areas where certain rules don't apply. Writing wouldn't evolve if people weren't in the habit of messing around with it on occasion.