It is unclear who originated the idea of a men's building, but it may not have been the men students themselves. The arguments used by two prominent women at the university suggested that they thought men were more poorly socialized than women and that a men's building could help men become better members of society. In spring of 1907, prior to the formation of the Minnesota Union in 1908, Professor Frances Squire Potter spoke at a faculty banquet and argued that a men's building would contribute to men's development. She expressed concern that American culture was being "left to the mercies of the women," while men were "in danger of being absorbed into commercialism and politics."
Later, Professor Ada Comstock, who was Dean of Women and a major proponent of Shevlin Hall, wrote of the importance of a men's building. She spoke of how necessary Shevlin Hall was to the health and development of the young women of the University, but that the men needed their own building more than women ever had, suggesting that women had many advantages over men. For example, she wrote: "A girl is exposed to few temptations: a boy, to many" and she described the men at the University of Minnesota as "hardly better than a mob." Her argument that the men resembled a mob may have been rhetorical and stated mostly to contrast the benefits of a women's building to the lack of a men's building, but it certainly is reflective of contemporary views of masculinity and femininity. Unsurprisingly, when the men began to agitate for a building, their argument differed somewhat from Comstock's.
"Dean Ada Comstock Speaks up for Girls and Professor Potter Takes up Cudgel for Men at Faculty Banquet," Minnesota Alumni Weekly, May 20, 1907, 11-12.
Ada Comstock, "What the Building Means," Minnesota Alumni Weekly, March 21, 1910. 4-5 https://conservancy.umn.edu/bitstream/53313/1/umaaMag-009_4.pdf