This is where you're wrong. A well designed game could be played 10 minutes a day. And I disagree, there aren't really any significant decisions to be made in the game right now. The only real tactic is to swarm outpost and colony ships all over the place. Everything else is actually "autopilot" after that.
Decisions can be made quickly. If the gameplay actually focused more on making meaningful decisions a few times a day, it would be much more interesting. Make it more strategic, more tactical. Right now it's just swarm outpost ships, build up more resources than the next guy, build huge stack of ships, and start smashing his planets. Even putting aside the issue with Traders, this style of gameplay rewards the guy who sits there 10 hours a day maximizing efficiency by not "wasting" any time offline.
Right off the top of my head, I can imagine a (somewhat artificial) mechanic that could sit right on top of the existing gameplay: Limit the number of orders you can give a ship/fleet/colony in a given day. Make it so that each order is meaningful and measured. This way everyone gets the same chance to take actions, and you don't gain an enormous advantage by being willing to sit around all day shuffling ships around.
Anyways, I know they are planning to add some stuff to limit land grabbing, which is good, but there is still more to do. I really can't stand the colony defense situation as implemented now. It is still too hard to do anything about colonies once they get big enough (unless you're one of these guys who builds 300 battleships per hour), and conversely once yours gets taken you have almost no chance to get it back. I severely dislike the whole "all or nothing," "rock paper scissors" vibe of attacking planets. I would much rather see a system where attacked colonies sustain "permanent" damage (of course you could "repair" as some kind of factory action) so that you don't risk suiciding huge fleets with no gain whatsoever if you miscalculate or mis-guess the strength of the defenses.
The way I'm seeing combat playing out is that you work in your little corner of the universe building up an empire, you put a decent amount of time in, you think you're doing ok, and then the next thing you now, someone shows up with a 500 ship fleet that you have no chance against, and the game is effectively over for you. It's dumb and boring if you're not willing to be the guy doing that.