So if all highend gear needs to be transparent and non-transparent gear is not highend? I own it specifically because it's not transparent.
I think this is one of those is the glass half-full or half-empty sort of arguments. If our goal is to archive the music the best we can then in my mind that means being transparent from start to finish. If a preamp, A/D, or microphone adds more low-end, mid-range, or top-end, then that's not really what the audience heard. Is this bad? Not really because in some cases the recordings hide some of the crappy mixes. But, if you really want to do the show justice, you simply try to get a very flat recording (transparent) that you can EQ later if you really want to. This is what on-location recording is all about. Studio stuff is totally different.
So, why is this like the half-empty, half-full argument? Because in the end there will usually be some type of EQ going on. If you like a bit more warmth, you can EQ your tape to sound that way afterwards. However, if you have a pre-amp, Mic, or A/D that adds that warmth without the EQ then you don't use EQ. The end result is the same.
In my opinion (aren't all things like this??), a preamp should never add or remove anything (regardless of high-end or low-end). It should be transparent, but again I think this is simply a difference in philosophy and not in the end result.
Wayne