It should be pointed out that many people have no problem whatsoever with stevia, but there are a number of people who dislike it. There are usually three reasons behind this: They don’t like the taste, they are concerned about their gut health, or they feel that stevia is too close to an artificial sweetener for their liking.
Taste
As with all foods, taste is subjective. What is loved by some can be hated by others. Stevia has a unique, bitter/sweet taste that reminds some people of liquorice. The aftertaste, in particular, is often cited by people as a reason why they avoid stevia products.
Gut Health
While stevia is deemed completely safe by authorities, there is mounting evidence that non-nutritive sweeteners (which include stevia) may cause harm to gut microbiota. Nettleton et al. (2019) found that stevia consumption altered gut microbiota composition in rats over a 12-week period [2].
Now, there are lots of foods that are perfectly safe but can also alter gut microbiota, but if your gut health is of the utmost importance to you, then it is understandable why you would want to avoid non-nutritive sweeteners such as stevia.
Lab Made
Whether you personally class stevia as a natural or artificial sweetener, it is certainly true that it is not as natural as many companies would like you to believe. Nor, in fairness, is it as artificial as many suspect. It represents a middle ground. But whatever you believe, it is understandable that many people dislike stevia for this exact reason.
These are the three reasons why most people dislike stevia. There are some people who dislike it for other reasons, with many complaining that it can cause upset stomachs, constipation and bloating, but these are tied to reason #2 (gut health).