You are absolutely right - your example answers could be applied to any top consulting firm. While the answer won't necessarily be marked as "bad", it also likely won't impress the interviewer and show them that you've done your research and you really want to work for the firm. However, they are still relevant - the flip side of the coin is that at recruiting events, most of the marketing information given out by firms could also be applied to other top firms.
Some tips/examples of what you can talk about:
- Being impressed by specific people/events: attending recruiting events (or any other event) hosted by a firm is one of the best ways to give a good answer to this question. For example, "I attended the Women in Consulting event at my university and was super impressed by the partner who presented and all the people I met"
- Find firm specific differentiators: MBB are more similar than they are different, but they do have some differences which you should highlight. E.g. for a Bain, an easy one is strength in Private Equity.