Találtam pár lehetséges választ, szintén csak tippek úgy tunik:
1.Stormbreaker is made by the same makers of the infinity gauntlet.
2.Stormbreaker was designed to kill Thanos.
3.Thor was a bit pissed when he threw it. (:D)
4.Thor gave a large amount of supporting lightning to his throw.
5.Thanos didn’t know it was an extraordinary axe, he likely didn’t bring the full might of the gauntlet to bear as he didn’t want to burn it up pre-Snap. E.g. “when I swat at a fly, I don’t use my full force because I don’t expect the fly to be stronger than most flys. Thanos didn’t realize what Stormbreaker was or the force behind it until it was too late.”
6.In the film, the beam never touched the axe, it was deflected by a rainbow coloured barrier. It’s likely that the shielding from the dark energy helped to deflect the blast.

A legvalószinubb és kézenfekvobb ezekbol sztem az, hogy Thanos egy normál repulo tárgyat várt csak becsapódni némi villámmal spékelve ami ugye számára semmi extra és nem egy Thanos-killer isteni csatabárdot, ezért eszébe sem jutott az Infinity gauntlet-et használni.