The big reason for this iirc from various meetings was a number of maps systems that wanted to be able to say they were purely standards based, so they needed t

The big reason for this iirc from various meetings was a number of maps systems that wanted to be able to say they were purely standards based, so they needed to be able do everything from within purely SVG. Recall that at the time XHR was just part of the general html spec - so there was no separate networking API that could be used _directly_ from svg. At this time of history SVG also was running on a belief that the correct solution to differing performance constraints was to have profiles. The high and low power profiles were not compatible such that you could easily end up in a position where you had content that could not display correctly in both at the same time.