I've also been on this tour and whilst this hotel does cater for Saga holidays too, I even met someone I'd met on a previous JY tour who was holidaying with Saga, there were also younger people, couples, etc there.
I'm normally one of the younger people on these tours (early 40s), but I find everyone easy to get along with, and the 'oldies' are often great company and have some great stories to tell. Most of us are young at heart, and as this tour usually has a lot of people on it, you're bound to find other like-minded travellers.
I really enjoyed this tour, and you can do as much or as little as you like, depending on whether you want to see all the sights or relax by the pool or go for a walk along the beach or to the next village.
I hope you enjoy this holiday if you do decide to book it.