I've seen 6:5 in two types of locations: (a) single-deck games and (b) high traffic locations (like the open area of the Flamingo facing the Strip.

Players who gravitate to single-deck like the game because they believe they can "count" cards, and/or because the deck is shuffled after just several hands. Players who frequent the high-traffic locations are casual players who are looking for action.

Either way, the additional 1.4% edge that 6-5 gives the house is minimal with those factors. While that edge is enough to dissuade more "serious" players, it really amounts to almost pennies for casual ones. For example, I've seen the average bet for 6:5 tables are generally $20. The 1.4% edge equals to 28 CENTS.