…grammar rules have been changed. We no longer have to write "because of…"
I have seen "due to" usage in so many press releases that I think the strict grammarians of my school days in the 40s and 50s have lost.
If you think about it, correct grammar and spelling are what people actually say and write, not what some grammarian dictates. Even French, with the French Academy defending it, is changing and has been changing. If you listen to French radio you will hear "le weekend" about as many times as you hear "le fin de semaine".
Did you notice another "rule" that I broke? I avoid putting punctuation between quote marks unless the punctuation is part of the quote.
Consider
Did he say, "I don't believe that?"
and
Did he say, "I don't believe that"?
That is, did the quoted speaker ask a question (first example) or did he make a statement (second statement)?
