Actually, they do: the wormholes work exactly the way physics says they ought to. What you mean is that stargates don’t work that way – which difference is explained by the techniques stargates use to inflate wormholes on demand (briefly, stargates use heavy entangled masses per the ER=EPR mechanisms suggested by Susskind & Maldacena, et. al., to comb the foam for suitable wormholes, then grab and inflate one per jump). Static wormholes, which also exist, work perfectly physically.