Yes it doesn't hurt as you say but conversely it may also do good
It does however hurt if you want padding as mentioned and then you could use one of the hacks instead.
I'm not saying add it to every element but only your main containers or containers that hold more than smple content. Indeed it won't fix all issues but it will help.
Elements with negative margins and elements that hold floated or absolute content should really have a layout but you wouldn't apply it to normal paragraphs or divs that just hold static text etc.
The problem with haslayout is that the error may not show up until later on and somewhere far from the original cause.
It's another choice that you have to make for yourself.