Patent examiners are given a relatively limited time/resource budget to examine applications. For that reason they will often reject early as a strategy [ETA: often, in my experience, with very weak "prior art" that basically matches some keywords], then allow more dedicated inventors to revise. This is mainly a filtering strategy, as best I can see. When your attorney quoted you $10K and suggested the patent would eventually be accepted, they were speaking as someone who understood the business and how the process would play out. It's surprising to me that you disregarded their advice and sunk $5K into the process only to walk away. Better to spend nothing than to waste $5K and get nothing from it.