Why would people who know biology have problems with limbed snakes?
Some DO have what is called “vestegial legs” (Pythons and Boa Constrictors) and one of the earliest ancestors was fully limbed. It is VERY clear that at one time snakes had limbs.
The only reason to NOT know this is either a lack of education or a desire to dismiss everything that vaguely supports a religion’s “mythology”. If it be myth, it’s likely to support something they noticed was happening, so there is no reason to fear something like that being purely fact. As for the education, yeah, sometimes they skip something that should be taught.
In fact, if you were eating Python in a world that wasn’t ours vs a viper, I’d probably call it a limbed snake.
And the only reason I disagree with calling them vestegial although they clearly lack the lower leg on the hind limb is because larger creatures often need the extra support for birth or laying eggs, thus making it necessary for a continuation of the species, NOT anything vestegial that can be lost.
Hell, a divergent world and maybe they didn’t lose their legs.