> It was found that many publications that use Unicode Braille characters use U+2800 with a marking glyph. A marking space is not without precedent, consider U+1680 OGHAM SPACE MARK. However, in some cases, U+2800 is clearly used as a symbol, to indicate the presence of a space when describing a Braille sequence corresponding to a symbol or punctuation, similar to the use of ␣ (U+2423 OPEN BOX) to indicate the presence of a space. Especially in cases where it is used in a trailing position, as in the [UNE13] example, it is clear that it would be inappropriate for this symbol to disappear.

> Considering this usage as a marking symbol, together with concerns about changing the relatively stable—and often hardcoded—White_Space property (a property of only 25 code points, last changed in Unicode 6.3, when U+180E MONGOLIAN VOWEL SEPARATOR ceased to be a space), the PAG preferred a more targeted change.

This doesn't seem that unreasonable.