I'm pretty sure I'm not really comparing the game when I tell people and agree that there isn't much depth to it.
What game can Sins be readily compared to? There are no RTS space strategy games, which allow you to research in real time and strategic zoom from the galactic map to the tactical map. I'm interested only in seeing a better Sins, not having it become more like another game.
The game gets boring, because there is not much depth, not much to do. What there is to do, takes a lot of time in that you sit and wait for research to be complete and check a few star systems and build a few ships and wait for you resource banks to fill before repeating. There is a stalemate oftentimes with the lack of variety in the units, to the designers credit there is no way to really have a runaway economy which prohibits smaller empires from staying competitive to a point.
However I think it would be much more enriching to do that both economically and tactically by introducing the ability for players to create their own custom ship design and matching them up against their opponents on the fly.
Sure its not fun to play on the same map for 20 times Vasari vs Advent but thats where the mods come from. Its like AOM, great game but gets boring when you finish campaign and play with all civs, then you get bored. then you go and enter online and theres a ton of different maps with different gameplay. that gives it a really high replay.
I'm not sure if you've played online, but players have largely jumped offline because the online game takes too long to get spun up in the larger galaxies. Its great for friends who play long games together but just strangers, forget about it. The online game also has boiled down to a few distinct strategies, of two or three key units which match up and over counter the others. With more unit variety there would be improved gameplay. For the most part its just LRM's versus FLAK. Every other unit is submissive to these two.
Mods are great, but few and far between, Uzi's planet mod is one of the best and adds the most, however the modding community for Sins has yet to really get traction.