I agree with the sentiment, but I think you forgot Strasburg (and Matusz & Gausman?? ).
Other college pitchers in first round that did/doing well - Chris Sale at 13 in '10, Max Scherzer at 11 in '06, Walker Buehler at 24 in '15, Marcus Stroman at 22 in '12, Aaron Nola at 7 in '14, Jered Weaver (before arm fell off) at 12 in '04, Tim Linecum (before arm fell off) at 10 in '06, and maybe Trevor Bauer at 3 in '11. That's not a lot though - college position players have had better outcomes.