Homeopathy is mainly considered "BS" because science doesn't have an explanation for why negligible doses of a substance can have great effect. It is a "counter-intuitive" theory on that basis.
However, this is mainly said in ignorance of other official theories. Science does have theories for why a small amount of substance can have a great effect. Consider traditional legacy vaccines. The theory was to give people small amounts or parts of a virus, or even a small amount of a toxin created by a germ, so that its effect was imperceptible but their immune system could recognize it and build immunity.
Look at Toxoid vaccines:
https://www.hhs.gov/immunization/basics/types/index.htmlToxoid vaccines
Toxoid vaccines use a toxin (harmful product) made by the germ that causes a disease. They create immunity to the parts of the germ that cause a disease instead of the germ itself. That means the immune response is targeted to the toxin instead of the whole germ.
Like some other types of vaccines, you may need booster shots to get ongoing protection against diseases.
This sounds oddly similar the the claims of Homeopathy. The substances in Homeopathy are also small amounts of toxins. I don't see why even a slight trace of it can't be enough for the immune system to recognize its injury at a micro or cellular level and try to build immunity.
One could even argue that a very small dose of the toxin would make it clearer to the cell of the immune system it is affecting on what needs to be done to contradict the toxin. Logically, a slightly injured or annoyed immune system cell can better understand and develop resources to guard against it than a severely injured or dead immune system cell can.
Logically, too, it can be reasoned that without the sensitivity of the gut immunity system, developing the immunity analysis elsewhere in the body where disease exists might be more difficult. The cells in the gut are said to be the basis of the immune system.
See this description on homeopahy from its inventor -
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1676328/Hahnemann believed that if a patient had an illness, it could be cured by giving a medicine which, if given to a healthy person, would produce similar symptoms of that same illness but to a slighter degree. Thus, if a patient was suffering from severe nausea, he was given a medicine which in a healthy person would provoke mild nausea. By a process he called ‘proving’, Hahnemann claimed to be able to compile a selection of appropriate remedies. This led to his famous aphorism, ‘like cures like’, which is often called the ‘principle of similars’; and he cited Jenner's use of cowpox vaccination to prevent smallpox as an example.
From WebMD -
https://www.webmd.com/balance/what-is-homeopathyHow Does It Work?
A basic belief behind homeopathy is “like cures like.” In other words, something that brings on symptoms in a healthy person can -- in a very small dose -- treat an illness with similar symptoms. This is meant to trigger the body’s natural defenses.
Homeopathy claims that it triggers the body's natural defenses. A number of similar checkboxes seem to be marked, and its creator even compared it to the vaccines at the time.
Indeed, homeopathy groups claim that clinical trials have shown that homeopathy has clinical effect:
https://homeopathy-uk.org/treatment/evidence-for-homeopathy/“To conclude that homeopathy lacks clinical effect, more than 90% of the available clinical trials had to be disregarded” -- Prof Robert Hahn, Homeopathy: Meta-Analyses of Pooled Clinical Data, 2013
As you look into it, it seems more and more possible, and is not clearly "BS". There is a body of what looks like evidence there. This is why the public is not debating Homeopathy, and by extension, has noticeably lessened its debate against Flat Earth Theory.