I appreciate your response but my question is the reverse.
Based on avrc's comment, the current beta is delaying 1.5 (the patch people care about).
What I understood is you are asking why a Beta branch is delaying patch. Please correct me if I am wrong.
The reason is that Beta branch will be Live pretty soon so crashes on it needs to be fixed. The reason for Beta branch was to allow people play upcoming patch on Beta branch if they desire so. It wasn't to get rid of delays due to fixes. So we cannot get 1.5.0 patch on Beta before moving 1.4.3 on to the Live.