I laughed ever time someone snidely or sarcastically told me "an Andorian/Vulcan hybrid can't happen" because if humans can make babies with Vulcans and Klingons, Andorian/Vulcan can happen. I mean, come on people, it's Star Trek.
That's right; it's Star Trek - not Masters of the Universe.
Science fiction is supposed to be believable. Some people will point out we already have warp drive or the transporter (though neither are as flat-out impossible as a non-engineered Vulcan-Andorian hybrid) but that is like saying, "You shouldn't have a problem with your dog shitting on your bed because he already pissed on the rug."