There are multiple different issues here-- different groups of non-Epicureans and also Epicureans who have pleasures that may conflict with ours (which Cassius brings up). Others who can't or won't try to have pleasure. Individually, we can treat these people using our own hedonic calculus.
However, it will be a failed project to promote the philosophy if we are not clear about who our audience is and what we are advising. That is why Epicurus was a dogmatist. His intended audience was the group he thought could make use of his words. He didn't spend time trying to find alternative philosophies for people who couldn't or wouldn't apply his, and he didn't hedge on his positions.
Because this is such a rigorously thought out philosophy, trying to apply it in an eclectic way or use it only part-time is like trying to stand in several boats at once. It confuses people who are trying to learn and who could potentially benefit from the actual philosophy. To be a public guide in EP means to aim the teaching clearly and consistently at people who can use it.