Frogboy: First of all, it's not much to ask one or two employees to release balance patches at regular intervals. Many other developers do this. Second, certain problems break the game, such as the AI being unable to build farms. These are major bugs that must be fixed otherwise you are ripping off your customers.
Instead of blaming your customers for mixed reviews, maybe ask yourself why the reviews are mixed. GC3 is just not on the same level as GC2, or Civ 5 or Civ 4. And even GC2 wasn't on the same level as many other TBS games. There were tedious things that made the game unfun, such as having to build a bajillion starbases and a bajillibajillibajillion constructors. In Crusade, you've gone a long way to addressing these problems, but in doing so you created an AI that couldn't build farms for at least a month (I'm assuming you've fixed this, though that is still very much up in the air), and during that month the game was unplayable.
I noticed that you guys fixed the extra movement bug that I mentioned on these forums, and that's great. Yes, there is a lot of noise, a lot of people are asking for a lot of things and you can't please them all. There are certain things that you really ought to be doing, though, as a developer, like fixing bugs, such as the AI getting 30 movement at the beginning of the game or not being capable of building a farm. As long as you are fixing bugs and rectifying any absolutely glaring balance problems, you're doing your job as a developer and your sales will show it.
Also, you guys are not alone. Every developer is going through these problems right now. Look at Civilization 6. Holy cow what a mess. The community has been griping about it nonstop, and justifiably so. I suppose what has happened is that the bar is just that much higher these days. People expect that when they buy Galactic Civ 3, it will be just as polished and fun to play as Galactic Civ 2, even though GC2 had years of expansions to further its development. Basically, no one wants to take a step backwards. No one wants to buy GC3 and then find its an inferior game to GC2. This is the problem Civ6 has, and its the problem Civ5 had as well. Part of what's happening is that you are a victim of your own success. When your company has produced the game that is GC2 with ToA, people expect that the next iteration of the series will be even better.
And don't hide behind the "indie" excuse. You want people to give you a free pass because your game is "indie"? then it should be priced at 17 bucks. I bought Planetfall and played it for 30 hours. There's nothing left to do in the game, it doesn't have much depth, but it was worth the 17 bucks. Same goes for Factorio. I played that for 80 hours and I'm done, but it got a good review from me. GC3 is not an indie title. You may not consider it triple A, but it's priced as such, and so it will be judged as such.
Don't blame others for the mixed reviews. You want better reviews? Earn them.