(Based on an Aalim's view)
Quran-alone Islam focuses on Quran, distancing itself from corpus of Hadith. This is like a reform movement among a section of Muslims, calling Islam a way of flourishing and successful living. But more importantly, these people saw the rise of western science, marvel of modern technology, socio-political power, human rights and other civic reforms gaining ground around the world (now to some extent also in Saudi Arabia). They think that Islamic world was being left behind against the power and achievements of the West and became too weak to stand up to it. They throw the blame for their weaknesses on what they think is traditional Islam, its power of clerics, which has held their societies back in race, not progressive enough to cope with the modern forces of the time.
In contrast,Quran-alone call for Quranic vision of life, away from the clutches and influence of traditional Islam that they believe are placing Muslims at receiver end. The mainstay Ulema of traditional Islam however reject such narratives, calling it a Fitna of ‘suit-boot-and-tie’ kinds of Muslims, who are only charmed by modern fascination. They deride the notions of modern or progressive Islam despite being Quranic. In their views, traditions are necessary that hold Muslims like in fence to keep them from drifting away. But Quran-alone think that fence only keep flock of sheep.