I think you hit the nail on the head when you said, "You can't return to the natural brick but who would want to." The first part of your comment is the key - You can't return to the natural brick.
Yes, people paint their brick fireplaces and exteriors a great deal. And it can look very nice. The 'trouble' may homebuyers and homeowners don't realize is that in doing this, 1) you've changed a maintenance-free 'covering' into one that requires maintenance, 2) it does reduce the value of the home, 3) since brick is meant to breath, by painting it, it can no longer breath and the moisture underneath will tend to 'blister' the paint especially if a home is 'humid' and if a fireplace is used, and 5) the vast majority of questions on the Forum regarding painting brick seem to be asking 'how to remove paint from brick'.
Certainly, you are enjoying your painted brick fireplace. And your recommendation to cover the brick with wood and mouldings is a very good one. (In fact, you and others have recommended this option in the past.) However, if the entire fireplace is brick, it could be a hazard DEPENDING on how much brick one wants to 'cover', and on whether it's feasable or not. (As an example, in my home, it's not safe to wood-over and/or paint/finish with wood because, well, it wouldn't look too nice and it would probably get ruined from heat.) We DO have an oak mantle around the fireplace but it's very 'high' up and off to the side. In short, the wood 'compliments' the brick. (If this is what you're referring to, it is done all the time.)
Neither here nor there. I just thought I'd explain a little more about what the original poster wanted to do and how I (and others) may feel about it. In the past, I use to 'refer' people to other posts where the Poster was looking for info on how to remove paint from brick. And some of those posters would say they tried 'EVERYTHING' and still couldn't do it. So you see, from my/our perspective (ie., those of 'us' that recommend against the idea), are the ones hearing a different 'tune' from the public. So with that, you tend to take a 'position' on the matter that would seem 'harsh'. Again, please don't misunderstand 'us' - It can be done but be informed of the 'bigger picture'.