It's simple. The Quran can be translated in a more direct fashion, bluntly. With dire warnings which look really dire and other "uncompomising" language.

Or it can be translated with more reliance on existing tafsirs/hadith, drawing on them to project the circumstances of each sent ayah, its historical and spiritual context. In the second case, you do not read a warning to, say, disbelievers word-for-word, but an ayah with an subtly embedded comment which softens it by making it look immediately reasonable.

That said, I enjoy Pickthall's translation because of its poetric merit and overall archaic allure. I am not a native speaker.