Marginalised agrarian societies are suggested to be the most vulnerable to environmental hazards and other perturbations. There are competing explanations for this phenomenon, which include: a lack of development, global environmental change, and the development process itself, or capitalism more specifically. All three causal arguments are compelling, but typically offer only partial explanations. With most societies experiencing significant capitalist-driven agrarian change over the last few centuries (e.g., depeasantisation, dispossession, proletarianisation), the critical agrarian change literature is biased towards these studies. Here I explore one of the most marginalised societies in Papua New Guinea, the Bedamuni People of Western Province. After 60 years of Western contact, at the time of fieldwork (2018), they remained shifting horticulturalist who had not been disposed of their land, had no commodity production and very limited opportunities for paid work. By exploring agrarian change within Bedamuni society since first Western contact (1962) and the arrival of missionaries (1968), and employing the concept of critical junctures, I critically unpack some of the root causes of heightened socioecological vulnerability. In the Bedamuni case study, and likely in many other societies, it is not just lack of development, environmental change, or the development process itself, it is all these things, and more, concomitantly. With the resource and commodity frontier almost upon them, and many Bedamuni desiring it to come, it is critical to understand the root causes of growing hunger. I argue that the development approach being driven by powerful actors will not meaningfully address this crisis and, in fact, may exacerbate the processes and factors that have produced heightened socioecological vulnerability. This paper problematises essentialist, universal narratives about the drivers of vulnerability in marginalised Indigenous societies in the global South. Whilst universal explanations can be insightful, we must not forget the centrality and specificity of space and place in development research.