I is one good girl. I likes banana and drinks five glass water the day.
The above sentence is wrong. It's very, very wrong. It does communicate as all the necessary information is there but, it barely counts as English, let alone good English.
I guaranty you that there is a language that would accept this sentence as proper, if it was translated, of course.
This fact serves to illustrate that the rules which we use and take pride in to construct prose aren't the only rules out there and the significance we attach to certain phrasing styles is based on what those before us have determined, as well as popular culture, not to mention many centuries of invading peoples.
What we can learn from this is...
Harshness has no place in the enjoyment of writing and neither do strict rules on how to do things!
I don't advocate clumsily strung together sentences and blandness is probably the worst thing that a story can communicate. I also don't like bad grammar.
However, there is wiggle room.
I'd really appreciate it if people stopped telling others that there's one way to do things. Not even the grammar and writing books agree with you there.
There's more than one way to do things in this world. Stop being so rigid, unless you're one of those English teachers or Literature professors, you know who you are. If so, it might be too late for you. You'll prove to be a good life lesson for your students on how to deal with difficult people.
(I'm not saying English teachers are inherently bad. I had plenty of good ones. Literature professors on the other hand...Well, hope springs eternal.)