Bro,,,, keep this a secret but,,,, you can do that yourself. It's true
I know of course. But you have to do a full install from said .iso file, and then apply the translation patch. Installing a Japanese VN can be a bit of a PITA, because you cannot read what you are doing. Sure - You can get away with some trial and error, but then you still have a game directory that consists of a bunch of Japanese characters. Often you also have to apply a crack (I don't know if that's the case here), and of course the instructions are in Japanese too.
Sure it's all doable, and in some cases even easy. However, it's far more convenient to have a single zipped game directory file that you can place anywhere and just play. It's not that I am not capable, but I have the choice between jumping through hoops or simply unzipping a file, then I choose for the latter.
Yes - I am lazy. My apologies and sorry, but sometimes I prefer the easy way.