Maybe Epicureanism was not intended as a guide for people trying to come up with their own recipes for their lives. Maybe Epicureanism was designed as yet another concealed ideology for people who are perfectly fine with buying a cookbook and never stray from its content.
Epicurus started teaching philosophy because he thought he had a system superior to all the others that were teaching during his time. He no doubt felt he had 'figured it out." I get the impression that one didn't join a school - did not seek out a school - to then "come up with their own recipes for their lives." To continue the metaphor, you liked the menu of the school. That's why you joined the school. You ate the food, learned the recipes, you tried to recreate the food at home, you got feedback from the chefs, repeat.
I don't think the "ideology" was concealed. I think the ideology - I'd say the teaching and tenets of the school - was completely on display, like a menu posted at the door of a restaurant. That's why people joined.
I want to state explicitly that there's nothing wrong with charting one's own course, taking a cafeteria approach to a life philosophy (to stay with the metaphor). Choosing dishes that work for the person. I took that approach myself in the past. However, I feel that starting with an established philosophy or religion or lifestyle gets you further down the road. It's not necessarily nefarious to want to use the cookbook from someone who appears to know how to cook.