Is it the initial price or difficulty or something else?
RPGs are still largely a niche genre with a small target audience.
Especially for indies without huge marketing budgets, AAA graphics and high production values.
KoTC2 is a premium product made for a very specific section of an already small audience. I think it may have been more financially successful if it had a higher budget for graphics, but that was clearly not Pierre's priority. I think if he wanted to make a great and beloved game for his specific audience, he succeeded,
but I don't know his goals.