I have pondered this same thought. These are some observations that I have made in various scenarios:
It's sophisticated; similar to but different from the type of sophistication of drinking wine.
It takes too long to prepare and requires too much effort; that doesn't work in a gathering of drinkers. The want to pop a beer can or pour some vodka in their Redbull or shoot ultra-sweet Fire Ball.
The niche is a "cult of oddballs". Typically, then and now, it is enjoyed by aesthetes.
The misconception by those that equate it to smoking marijuana. I have tried offering absinthe in gatherings, and as soon as I mention the word they look at me like "oh, you're a stoner."
The misconception by the ex college kids (that are now parents) that had shots or lit it on fire. See above.
Certain 'older' generations have never heard of it. Not willing to try something 'new'.
The intensely herbal flavor/s. A beer chaser doesn't work with it.
Difficult to serve in typical bars. Requires real estate for fountain. Busy bartender has to tend to the drip. This doesn't allow patron to appreciate the louche. Can't self-serve it like 19th century bistros; glasses, carafes, spoons etc. would disappear - too costly.
These observations are obviously typical for U.S. environments. I can't speak to the attitudes in other countries.
And it may just need more time. In another interest that I am involved in, the subject is just recently starting to gain in recognition. I have been involved with it for over 15 years.