Content of the speech aside, the grammar was incorrect. I, like many others here, believe it does matter. My argument is always that a teacher teaching English to, for example, a German or French person, would try very hard to provide accurate information. I’ve done it and would never have said ‘it doesn’t matter, say what you like’!
The other reason I believe this stuff matters is that both my fairly successful careers have been based on being able to read, write and communicate clearly in the English language.
If none of it matters, what on earth was the point? Depressing to put it mildly!