[development] Unique block titles why?

[Nic Ivy]

Why must the titles of blocks be unique?

I frequently need empty titles for several blocks, and to accomplish  
this I usually remove the unique index from the block table.  I have  
noticed no problems during the years I have done this.

Things are different in 4.7--the validation is done in block.module  
instead of the database index.  But the effect is the same.  Block  
descriptions must be unique.

Why?

Nic