Actually there is a really good reason, it has to do generally with making sure that all the aspects that you want evaluated are actually evaluated.

Now it may be possible with models like Astra that you no longer need to do this, but in earlier models it was beneficial.

So I might want a macro economic read which leads to a market thesis. Then I would hunt for exposure, then evaluate the candidates across different aspects. Breaking the process up at least made sure no steps were missed and the different aspects considered.