Isn’t the omission of a q mark just a matter of style
It is an error. Question marks are not optional when ending an interrogative sentence, e.g. "Do you understand English grammar?"
Question marks are optional at the end of commands or requests phrased as questions e.g. "Will you please send me a progress report by June 10th?"
Esp when the phrase is so obviously a q
It is especially an error in that situation.
Very interesting Con that you should so observe. (no 'the' before English grammar)
We don't use the definite article with uncountable nouns when used in a general or non-specific sense: e.g. nature, grammar, health, information, life, death, murder, love, hate, size, weight, etc.
As an erstwhile writer myself I can’t see anything wrong
So you feel "A tree is part of the nature" and "A tree is part of nature" are equally grammatical? or "The death comes to us all" and "Death comes to us all"?
(Furthermore......question mark. - there should be no space.))See item 1
I'll allow that this is more a question of typography or handwriting than grammar. In French a full width space is used before a question or exclamation mark. In English writing and printing this is called "French spacing" and it is an error.