Isn’t it odd that the science’ crowd will threaten, jail, fine, and hurl invective at anyone who points out that a) there is no genetic basis for homosexuality
No, the 'science' crowd point out that saying it must be genetic or else it's merely a lifestyle choice and/or a mental illness is a false dichotomy. It is entirely possible (and, indeed, likely) that the factors which cause any individual person's sexuality are only partially genetic. This utterly fails to make any sexuality, including homosexuality, or even heterosexuality, a choice or mental illness.
and b) suggests finding a scientific means of correcting or reversing it?
No, the 'science' crowd thinks there is nothing that needs 'correcting'.
If someone had only three fingers on a hand and a drug was discovered/developed that could restore the missing digit would that be viewed as negative or controversial?
A more accurate analogy would be if a fairly large group of people had a religious belief that people with ring fingers which are longer than their index fingers were abominations unto God and must be punished by stoning to death, and the people with long ring fingers had historically suffered some pretty intense discrimination, including being jailed for the crime of existing, or even killed, and this discrimination still happened in some parts of the world, and now somebody was trying to develop a surgical technique to shorten ring fingers - and some people are advocating that everyone with long ring fingers must undergo this procedure, whether they want to or not. Would that be viewed as negative or controversial?
If someone developed hormonal treatment (ie the same sort of treatment currently used to convert’ between sexes) that would eliminate homosexuality would they be praised or persecuted?
1) Gender and sexuality are simply not connected in this way. It is entirely possible for someone to be both transsexual and homosexual, for example.
2) This was already done, back when homosexuality was considered a crime, by the use of drugs that were basically a form of chemical castration, and is still done to the likes of child molestors. It causes various side effects, both mental and physical, and, due to this, some people consider it to be pretty inhumane and barbaric.