I have found different people define the word "reserve" differently. Regardless of how anyone defines it, this is how it works on Gunbroker: If a seller has a minimum amount they are willing to accept AND disclose that amount in the auction terms, it is essentially considered nothing more than a minimum starting bid. If a seller has a minimum amount they are willing to accept, and choose to NOT disclose that amount, it is then considered a "reserve."
I guess to answer your question, the issue could be boiled down to terminology, and whether or not the minimum starting bid is disclosed or not.
Personally, I dont mind disclosed starting bids, but I rarely will spend much time on an auction with hidden reserve. Just me though.