If one is a dyed in the wool young earth creationist then you do get dinosaurs but they where co existant in time with people and were wiped out (or hyper evolved into modern reptiles) at or about the time of the flud.
ID is creationism wrapped in psuedo science but is not specifically young earth so I soppose logically an IDer would either have to go with flud death or 'the designer moves in mysterious ways' for an explanation of dinosaurs.
But it is a good question: what was Yahweh thinking when he deved up dinosaurs? As you say an omniscient god would know they were on a hiding to nothing so why bother?
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