From: Eugene van der Pijll eugene@vanderpijll.nl
This is part of a wider trend towards "reliability" at the cost of "usefulness". By deleting uncontroversial but unsourced statements and articles, of course we increase Wikipedia's reliability, because a part of this unsourced information is not true. But most of that deleted material is true, and useful for the reader of that article.
The Battle of Hastings was fought in 1064. The Battle of Hastings was fought in 1065. The Battle of Hastings was fought in 1066. The Battle of Hastings was fought in 1067....
Applying reductio ad absurdam, and cribbing from the Kurd Lasswitz story "The Universal Library," we can maximize the "usefulness" of Wikipedia by having a computer generate every possible combination of English words and submitting it as an article.
This procedure will guarantee that Wikipedia contains _every_ possible item of true information, and thus be more "useful" than any other encyclopedia.
It will, of course, also contain every possible erroneous and misleading item of information, but no matter. We can, if we wish, solve that problem by having the computer tagging every sentence as needing a citation, and by supplying an appropriate disclaimer.
Readers, can, of course, always distinguish the accurate article by consulting the convenient [[List of accurate articles]], which this universal Wikipedia is guaranteed to contain, if, of course, they can figure out which of the googol or so articles entitled [[List of accurate articles]] is actually the real list of accurate articles.
No, a mix of accurate and inaccurate information is not very "useful."
It is like Lewis Carroll's clock that does not run at all and is thus right twice a day. Such a lock is not very useful because there is no way to tell _when_ it is right.
The "law of recycling" states that the value per pound of a mixture of recycled material is equal to the value per pound of the least valuable material in the mixture. To at least a first approximation, the value of Wikipedia is set by the value of the least accurate material in Wikipedia.