I believe when it comes to sources, pre-amps, amps, and etc, the goal to be as accurate as possible is a good one.
The same is true with speakers, but a big caveat is that there is no such thing as speakers that are so accurate that you cannot tell them apart in a blind test. Fact is, no two speakers sound exactly the same. They will all have variations in their performance that is greater than the threshold of human ability to detect. The present conclusion is therefore that the current state of the art in speakers means the listener has to accept an imperfect audio reproduction device.
From that conclusion two different thought processes emerge. First the purists feel that even if you can't be perfect, you should still strive to be perfect. The argument here is that a more accurate speaker is ultimately a superior speaker. But as you get to a certain level of performance, the degree of accuracy between different speakers become asymptotic - they get close to but never achieve perfect audible accuracy. Furthermore, even if different speakers have similar accuracy, they would be inaccurate for different reasons, rendering them to sound different. So even purists will have to confront the second through process, which is to embrace the fact that there will be differences, and simply to choose which ever inaccurate speaker that best suits one's tastes. Take this a step further, and you have speakers like Wilson Art that gives up entirely on trying to be accurate and simply goes after a certain sound signature.
So my conclusion is that yes speakers can be voiced. There are good reasons for them to be voiced, if not simply because there really is no other alternative.