So, the parents gave out tickets. The shulchan Aruch says to give them candy and nuts to get them involved. The parents did what the SA said to do, and it worked. It even got a bored 13 year old involved. Nobody ever suggested sitting 5 hours or more at a seder table was easy for anyone, let alone a child.
Adults get bribed too. Manufacturers offers sales spiffs to sales people. Retailers employ all sorts of gimmicks and giveaways to get people to shop. Many large employers offer employees perks as a means of retaining their services. Some offer performance bonuses. Want to call it an incentive instead of a bribe, go ahead. It is just a matter of semantics. Candy speaks to kids, aat least those of your relatives.