Because 2...Bc5 is bad as 3 d4 wins a tempo.
I think we've invented theory , what do you think ?

Because 2...Bc5 is bad as 3 d4 wins a tempo.
Then why is 3.d4 never played according to chess.com's explorer database ?!

According to the database 3.Qe2 3.d3 and 3.c4 have been played in that position but not 3.d4 , why is that ?
Also , why does no-one play 2.Bc5 3.d4 in the Knight Variation of the French Defence after 1. e4 e6 2. Nf3 ?