Hmmmm that generalized a bit. ISI is created for recreational skaters, where kids and adults are equally likely to quit after progress stalls. When qualifying to eligible competitions is not the ultimate goal, it's fair to emphasize the fun factor and keep skaters in the sport. Really, one can be as serious as s/he wants at an ISI competition, the lighter options are just a possibility to get loose. It's not like USFS adult nationals don't have similar events.
Not all group lessons are genetic and introductory. It depends on the class size and coach's ability to challenge everyone. If it's a good group class, keep it alongside privates: different perspective and camaraderie.