I don't really think Stardock wants everyone to be holding the bag if they go down and I have to believe that they want to serve those that paid for their game but you have to make choices right? We understand that the code needs to be protected and I can accept that but put in a system that makes sense, I don't appreciate going through hoops for no reason and I want to keep my fixes on my hard drive. I want to be able to install them on a computer with no internet and I want them in case SD goes offline. Its a totally reasonable request!
First of all, after patching, the game requires online activation. Impulse handles that silently and invisibly. A standalone patch would not help you if Stardock's servers are down or gone, since they are required for activation regardless of how you acquired the patch.
Secondly, Impulse patching works by checking the check-sum of every installed file against the one on the server, and downloading any that mismatch or are missing. This results in a minimum of required data transfer. To release a patch, Stardock simply updates the files on the server, update a version number, and replace the full download archives. Creating a standalone patch that can update any version to any other would not only result in far more strain to the download servers, it would also result in extra work for Stardock. Furthermore, a standalone patch that works just like Impulse does, with no extra effort, would be as big as the entire game, since every file needs to be there in case it is needed. Now, they do in fact have such a standalone 'patch', since that is indeed easy to create. It can be downloaded from http://anywhere.impulsedriven.com. It in fact uses Impulse to install the game, since that is indeed easiest. But it does require activation/unlocking, so it will do you no good if Stardock goes under.
No, Impulse does not prevent piracy. But it does prevent the Pirates from using Stardock's bandwidth to acquire their patches. It also results in them having to wait for someone to crack the new version, find out which files are changed, and create a standalone patch for them. He then has to acquire it, and install it manually. Using Impulse to auto-patch the game for you as soon as the new version is released is far more convenient for most people, which is the entire point.
You cannot prevent piracy without absolutely draconian methods, and even then you probably only delay them for a while. And after they have cracked your game, they have don't have to put up with said draconian copyright protection methods, making their experience superior. With Impulse, the customer's experience is superior: They can download the entire game from fast servers, even if they bought it retail. They have autopatching. Since the activation requirement is only added once you have used Impulse to update or download the game, and since said activation happens through Impulse, most customers do not even know said requirement exists.
If they would release standalone patches, users will come face to face with the activation requirement. The activation, since it no longer can happen automatically will become a hassle for customers. Sins of a solar empire was released prior to Impulse being ready. So they released standalone patches. None of those patches required the customer to activate their game. Then Impulse got released. They stopped issuing standalone patches, and silently introduced the activation requirement in the next Impulse-only patch. Since Impulse handled it silently, most customers to this day do not even know that Sins of a solar empire requires online activation. I had an argument about that with someone on these forums who could not believe the game had an activation requirement, even though he owned it. I had to explain all this and post screenshots of the activation dialog to convince him.
Copyright protection that is so unobtrusive that people cannot believe it is there is ideal. Stardock has never been Anti-DRM. They are Anti stupid DRM. Releasing standalone patches that will merely make their customers aware of their activation requirements is counter-productive for that reason, and therefore a waste of effort. Which is one of the reasons why you will never see standalone patches for Galactic civilizations 2.