Since male anal sex is called a toevah (abomination) in the Torah, doesn't it mean that it is an ethical evil that goes against Jewish hashkafa (morality)?

“Toeva” is a commonly misunderstood word. In the Torah (bible) eating shellfish and wearing shatnez (cloth containing wool and linen) are also called a “toevah”. However, one would be hard-pressed to label wearing a combination of linen and wool, or eating shrimp, as unethical or immoral.
It’s important to understand that while according to many interpretations, male homosexual behavior may be a biblical prohibition, there is no reason to think that it is immoral, dirty, or harmful.
We simply do not know why some things are prohibited in the Torah. It is this mystery that allows us to be humble and non-judgmental when it comes to biblical adherence and understanding.