Its primary purpose would be to prevent people from rolling out a fully developed and fleshed out character in less than a week, something that most people are pretty capable of doing on a normal shard. Siege Perilous is meant to be a hardcore shard - hence you do not get everything handed to you, including your characters skills. You have to work hard, put genuine effort into your character, and earn it.
It is also a shard that is based upon the concepts of player justice, and you cannot exactly have player justice when a griefer can delete his character and roll up a new one with a different name in less than a week. You also don't want every flavor of the month PvP guild to suddenly flood into the shard and create problems for the existing community.
Nonetheless, I cannot speak on behalf of Siege Perilous, namely because I haven't played there in a few years. On the other hand, I would take most of these complaints with a grain of salt. It may yet be the genuine opinion of a frustrated community, but how many thousands of threads have been created on U.Hall just because some negative whiner decided he isn't having fun, so he wants to ruin it for everyone else, whether the community agrees or not?
Honestly, in my experience on Siege Perilous, training a character does not take that long. The lack of uber-suits (because of no insurance) makes a unfinished character far more useful on one of these shards, and if you can't find anything to do in the month it takes to train, you aren't going to enjoy Siege Perilous once you have that character finished anyways. Its not the time that it takes to train that has left Siege so empty, its the fact that Ultima Online as a whole has fallen on hard times population-wise - many of the west coast shards are a shadow of their former selves, its not something isolated to just Siege.
