They remain just as abundant as they were decades ago. In other words, they appear to be resilient to the environmental changes that have occurred in the last few decades. Will they remain resilient in the future? It is anyone's guess.
It becomes such a dreary task to fix someone's grammar, but if I know that student, if I know he was just dumped by his girlfriend yesterday and tonight he's getting a new tattoo, it's easier to write "comma splice" 30 times on a paper and not get mad.