You are an asshat.Yeah , read the rulebook. Because your quotation the you are reading is clearly not a 'unclear rule' but more of someone who doesn't understand the rulebook. The rulebook makes it quite clear: you have to have the deep strike rule to be able to deep strike. The part where you are reading the deep strike rule is ONLY describing what occurs to units that HAVE deep struck.
This is a reading comprehension issue, and the only way to solve it is to read the rulebook.