I feel that's the limitation of oracles; or at least oracles like that, where a very specific meaning is written in the booklet or on the card. It's a lot different from tarot. There doesn't really seem to be much else to say unless you're just pulling it out of your you-know-what. lol
I use them for myself, but as for using them to read for others I don't see how it could be done in a way that justifies charging money for it. They don't really spark anything intuitive. They just are what they are. I mean, in this case, each picture is an angel so... what else are you supposed to get from it?
Either you're reading the card/book or memorizing it and paraphrasing it later. (Unless you're really doing psychic readings, with cards in your hands.)
Also, think of the ones with yes/no options. Would you pay $20 to hear yes or no? Kind of anticlimatic, but it is what it is. lol
The 'cool' factor with oracle decks, IMO, is drawing cards that actually align with your question. Most times they do, but sometimes they don't. Very different from tarot where every card aligns with your question, you just have to figure out how.
I know there are people who offer readings with these (and similar oracles) for money, but personally I wouldn't pay for it unless I was just really curious about the deck and had money to burn. Or the reader had a very good word-of-mouth rep as a psychic or medium, I guess, and I wanted that type of reading.
She might have been trying to see how and if these decks could be worked into her reading practice, experimenting with a new thing. You never know.
If you didn't like it/her though, that's fair. If you feel you have to, just tell the people at the shop straight out. I don't really see that it would be a big deal since it seems like you're friends with them by now.