I'll admit now to having not yet read either Kuhn's Rebellion and its Enemies in Late Imperial China (1980) or Prazniak's Of Camel Kings and Other Things (1999), which would probably give a broader view of the rebellions of the day. However, I have done a lot of Taiping reading, so I can talk about the Taiping in particular.

Essentially, there are two possible extreme answers to the question. On one side, you have what is essentially in line with the view of the Chinese Communist Party, which, espousing a Marxian view, would claim that socio-economic (indeed mostly economic) factors were the key in bringing about the rebellion. The opposite is in the vein of Reilly (2004), who posits that religion was in fact the linchpin of the movement, and that its political, social and economic aims stemmed from its religious tenets. Of course, there are more moderate proponents. Spence (1996) and Platt (2012) both suggest that the motives of the rebels were too wide-ranging and variable between individuals and sub-groups to generalise, and that other ideas, especially nationalism and traditional precepts of legalism and constitutional legitimacy were more significant.

There is merit to all of these positions. The Chinese peasantry were genuinely oppressed as a class and did, when the Taiping arrived, flock to the movement. However, I would argue that ideological factors were more important for a number of reasons.

Firstly, supporters of the Taiping did so usually with knowledge of the movement, and presumably its nature. Rather than many peasant rebels springing up across southern China, the Taiping banner was the specific target of support, and although religious observances were less frequent in the later stages of the rebellion, the performance of religious ritual was apparently no less fervent when it started. This would suggest that ideology was by no means diluted by increasing numbers of followers who were not the more explicitly zealous original converts.

Secondly, the Taiping leaders themselves made little mention of socio-economic factors in their propaganda, which for a movement that was founded upon a social divide would be highly suspect, but in a movement based on loftier ideology makes more sense. The idea of the post of emperor being blasphemous for having appropriated titles reserved for God, the non-Chinese heritage of the Manchus and the natural right of a new dynasty to rise – the Mandate of Heaven – were vastly more common.

To be fair, the Taiping's (presumably) unimplemented policy of state-owned, equally distributed land was technically in the common interest. However, why did they not approach the problem by simply redistributing private ownership? The Taiping land policy cites religious reasons – all are God's children and thus deserve the same land. Of course, the Taiping leaders could have been rather crafty in how they decided to present themselves, but even so, this top-down proto-socialism seems unlikely without that doctrinal influence.

Most importantly, the devastation of the war did little to dampen the zeal of the Taiping. Despite the fall of Nanjing in 1864, the last Taiping king was not defeated until 1866 and the last rebel army was active until 1871. A purely economically interested movement would probably long since have given up hope.

You can disagree with my conclusions – I'm not sure how convinced I am beyond the first two points I made – but I would say that the Taiping religion was an essential part in the distinctiveness of the movement and that to dismiss it merely as a disguise for seemingly deeper socio-economic issues is unreasonable.