Folks, this blog entry from Joel Kallman hits it right on the head, why a lot of people have issues with APEX....
(YABAOAE) Yet Another Blog About Oracle Application Express: You don't lack APEX skills.....you lack Oracle skills
Read it and you will understand..
A very well made point by Joel. He also alludes to a higher level where a knowledge of relational database design is also an important precursor to a successful application, regardless of the RDBMS or API being used.