Pretty much what we said last week mate, I knew it wouldn't be your cup of tea because I am the same and like a more linear game these days. Back in my childhood / teenage years I used to LOVE RPG's, really love them, nowadays I just haven't got the patience or the time to explore all of the map, read all of the dialogue and work on the million different skill tree options.
Just Cause 3 will be a massive game, I remember on Just Cause 2 I struggled to explore it all and got a little bored of it after a while for the same reason. The difference with something like Just Cause is it's full of explosions, gadgets, weapons etc. and is much easier to just pick up and play for an hour or two and feel like you have progressed or feel like you've had a load of fun. I don't get that same feeling with something like Fallout, Skyrim etc. They are fantastic games, but unfortunately just don't suit my gaming habits any more.
On Just Cause you'll be able to pick up a weapon and instantly kill people / blow stuff up, on something like Fallout you have to modify weapons, find bits to add to them, upgrade them etc. before you can really enjoy them. Of course there is enjoyment in doing all of that for a lot of people, but just not for gamers like you or I