That would be the Simple Green. It shows up as more damage with long soaks but even short but repeated use will dull polished aluminium after enough cleanings. I'm not sure if the orange based citrus degreaser I have used on occasion for motorcycle parts is corrosive in the same manner or not.

Oh, and I found that the local hardware store's housebrand orange citrus degreaser is way more effective than Simple Green. I had bought some SG years back for heavy shop cleaning but found that it really doesn't cut into the grease without a lot of brushing. And even then lumps or grease just float around instead of being broken down. On the other hand the orange stuff really cuts into the greases and oils pronto.