Qualitative data is about insights and observations from a small but well-studied sample. They lack the attraction of big numbers (in contrast to quantitative data).
N of 1 trial is getting more attention with medical trials, as it becomes insightful to look at diseases and treatments through the lens of a single patient. It gives context and observations about the interplay of many factors.
Still, it is easier to convince ourselves that some number based on the 50 responses survey (which is usually statistically irrelevant and prone to provide misleading insights) is more valid than an in-depth study of one person.
We easily can say: yeah, but that is just a one person, one behaviour, single situation.
To that, I say: if you have found a needle in a haystack, it is not luck. There are more needles (maybe more than the hay itself).