If nothing is selected, everything is selected ...

 From:  PaQ

That's the kind of behaviour I really appreciate in package like lw, modo. It might be handy for a couple of functions I guess, like the join, separate, show points (and probably a couple of others).

Join is probably the fonction I fire the most during a modeling task, and 99% I just want to join everything in the scene, so I always have to select everything (with ctrl-a or with the lasso) and then join. Is it any downside if the join fonction just join everyting in the scene if nothing is selected ? and of course only join selected geometry if needed.

Maybe it's just an 'un-natural' behaviour that I'm used to because of the main softwares I'm coming from.