How a Practical Apps DBA Should be

Hi,
I am a Senior Apps DBA.Worked previously with oracle.I share my experience here .How an Apps DBA evolves? DBA's normally start their career in Core Oracle atleast 2 years and start their career in Apps.People have a question normally--Is it really required that I should be Core Oracle DBA before starting my career in Apps?. According to me the answer is a big YES.Why ,Is it not necessary that one should understand all the concepts or go to a big training and directly land in to apps dba market.? Apps DBA's should understand first how the Oracle DB is and ins and outs of DataBase Administration(Core).Then only they can perform well as Apps DBA.One can well administer the Apps with no experience in core dba but he can not troubleshoot much on his own with out practical experience in Core Oracle DBA.My view is based on my experience.comments ,criticisms are welcome.
--Vivek