Past simple?!

Every English sentence begins with a capital letter. It is not optional. Without it, you have word salad that is hard to read.

soheil1can 'They insisted that'.... refer to the insistence being habitual?

No, not alone it can't.

Hypermodernists insisted that.......................

Surely Hypermodernists where present for some years.
So does it mean that the insistence was born with them, created with them, and continued through their reign?

I mean to ask if their insistence persisted and the simple past mean the action continued.
And What is it simple past and not past continuous or past perfe

Three words in isolation are rarely analyzable grammatically. Still, however long the Hypermodernists (how stupid do you have to be to put "modern" in your label?) existed, there is no way to tell from those three words how long they insisted anything. You would have to say more, like they consistently insisted or insisted as an article of faith or that they by the very nature of their hypermodern