Because leading Islamic scholars have decided it's ok. Just like leading Jewish scholars have decided that even the most orthodox Jews can drink fresh water, even though all water everywhere in the world contains microscopic creusteceans. Religions and belief systems don't have to be perfectly logical(not in the "ah gotcha" scope anyway).
To be fair, all that does to me is highlight the inconsistency and illogicality of these archaic religious customs, which were rooted in sanitation concerns at a time when no one knew what bacteria was, but have become venerated as part of a global control mechanism by the elite.
Every good cult needs a list of low-stakes, illogical rituals, because they serve as nuclei for adherence to higher-stakes illogical beliefs and acts.
Unfortunately, science has made it increasingly difficult to justify the absolutism of many of these religious practices, and so somehow these religions skate by by saying, "oh we're just being practical and realistic" even though they continue to stray further from the dogma which defines their religious beliefs.
It shows you unequivocally that these religious institutions are more interested in maintaining power than adhering to their own belief systems.
