arXiv:2611.13211v1 Announce Type: new Abstract: The integration of generative AI (GenAI) into user interface (UI) design has led to prompt-to-design generators (P2dGens), tools that enable designers to create UI prototypes from textual prompts efficiently. Despite their growing adoption, little is known about how designers use these tools in everyday practice, their benefits, and limitations. We conducted semi-structured interviews with 17 UI designers to investigate P2dGens use, focusing on workflow integration, attitudes toward generator-assisted design, and the organizational climate. Findings show that designers primarily use P2dGens as ideation accelerators rather than end-to-end solutions, and they adopt a variety of individual and collaborative prompting strategies. Designers expressed complex attitudes, noting gains in efficiency and inspiration while also highlighting concerns about loss of personal creativity and design quality. We also observed emerging governance practices and varying attitudes within organizations toward P2dGens. These insights illuminate how P2dGens reshape UI design workflows and contribute to understanding human-AI collaboration in UI design.