I think a good analogy can be seen in queueing theory. There is a natural limit to how long people will wait in a line, but it varies on many factors. People wait much longer in line for a ride at Disneyland than they would ever consider at a grocery store. But within each category, the service provider tries to find that sweet spot that balances costs with benefits.
Kitely offers very economical and efficient pricing, and the tradeoff is a world entry delay of seconds. In fact, if even one avatar is already in a world, the entry for a second avatar is instantaneous, so the wait process is almost negligible under many circumstances.
This kind of price versus benefit happens in retail. Stores with the lowest prices tend to have longer lines at the cashiers than stores with higher prices. It's not valid to say that any queue time whatsoever is a discouraging factor - people accept such a delay to receive the other benefits that go along with the wait. The same goes for getting into a popular club or getting to a preferred job in the center of the city (traffic!) or waiting for a seat on a plane for a vacation. It's all about tradeoffs in costs and benefits.