Maybe he was a hunter. Ibex is a high altitude goat. So his primary food was goat meat. Wheat grains also found. Not sure about his farming ability while climbing so much on mountains at the same time and hunting for goats.
In 2009, a CAT scan revealed that the stomach had shifted upward to where his lower lung area would normally be. Analysis of the contents revealed the partly digested remains of ibex meat, confirmed by DNA analysis, suggesting he had a meal less than two hours before his death. Wheat grains were also found.
Or he stole the hair of some unsuspecting metalworker, along with an axe.
High levels of both copper particles and arsenic were found in Ötzi's hair. This, along with Ötzi's copper axe which is 99.7% pure copper, has led scientists to speculate that Ötzi was involved in copper smelting.
He should be lactose intolerant, this conflicts the shepherd idea, or maybe this was some other form of shepherding for meat only. But it looks like a hunter/shepherd to me. His clothes is best suited for high altitude and cold climate.
By examining the proportions of Ötzi's tibia, femur and pelvis, Christopher Ruff has determined that Ötzi's lifestyle included long walks over hilly terrain. This degree of mobility is not characteristic of other Copper Age Europeans. Ruff proposes that this may indicate that Ötzi was a high-altitude shepherd.