That's usually actually down to technique - you need to fill "normal" blenders in a specific way to have enough liquid on the bottom to make the vortex.
It's also heavily dependent on the shape of the jug. For example, even just among Vitamix blenders, the restaurant-standard 5200 with the tall skinny container apparently works noticeably better than the 5300 with the low-profile (short and fat) container designed to fit under kitchen cabinets.