http://www.nettranslation.co.uk/resources_about_language_chinese.htm
Goes into some of the details, but the bottom line is that culturally and in underlying technical architecture, the two writing systems have differences, and more over, Simplified is "lossy" - that is there are characters which represent several characters of Traditional. More over there is, indeed, a political and cultural dimension here, which is no different than many other languages, namely there is a political dimension: from the point of view of a Taiwanese person, this action says that you support unification under the current mainland government, which may not be what you want to say to people.
The other problem not covered here is the most encyclopedia oriented one: looking up material. Names of places and people from traditional are now difficult to look up, since many of them are transliterated differently in simplified versus traditional.
I fear an overly hasty decision was made to stop what seemed like a "maverick" project, when, in fact, there are non-trivial, and non-technical user issues raised by "one or two". My personal preference would be for one: the problems of two character set worlds are a nightmare which are recognized around the world as creating difficulties between the three major sets of chinese characters in use (Simplified, Traditional and Japanese) which have just enough in the way of differences to make life difficult.
The three important technical/user issues to address are:
1. Disambiguation pages are going to be needed in larger numbers, as a reference in simplified which has multiple renderings in traditional. There should be some process which makes tracking down and dealing with such references easier.
2. Where there is a discontinuity in character mapping, the search should be made to work for both. Example: unicode maps "guo" (country) to separate characters between simplified/japanese and traditional. Someone typing in the traditional character would get no article, and be invited to create one.
3. Many sources are originally from "traditional" characters, and their simplified versions, as noted, are "lossy".
My suggestion is that some method of encoding an "alternate" traditional character be made. For example [[[ 干 | 幹 ]]] would say that in this context the simplified 干 should be replaced by 幹.