Yes, I often use this method too.
Unfortunatly, since Joomla 1.6, there is somewhere we cannot anymore do this (not for DB, but in Models or controllers. I don't remember where) so, to avoid changing the aliases depending of the context, I prefered to have a common alias everywhere (TABLE = VIEW = CONTROLLER = MODEL, ....). So I had to forbid the use of '_' in table aliases and layouts aliases. In first versions of Cook it was possible.
For example, what I remember, modal pickers lacks when you want to reach a layout named with a '_'.
Another very important reason, I had to limit, is for foreign keys :
$row->fkuser // Is a foreign key
$row->_fkuser_name // Is the joined value behind fkuser linked table ('name' field)
If you name a field "_fkuser_name" for instance, it will conflicts.
Same idea for the tables aliasing in SQL queries.