SVG was the result of an effort to make an open standard for vector graphics. As is typical for open standards, it wasn't an entirely novel concept. There were several competing alternatives; IIRC, SVG was one of half a dozen proposals submitted, and most of those proposals were evolutions of prior designs/attempts at a standard. While flash was an original design, it was as much a "reinvented Shockwave" as SVG was a "reinvented flash".
That's part of the original design goals for it. Scripting support has been part of it from the very beginning, to allow for time-based animation etc.
While scripting could be used for time-based animations, the preference was to use the declarative SMIL. Scripting support was intended to allow more sophisticated interactive graphics.
Hand authoring complex SMIL animations really sucks. The declarative nature introduces obnoxious limitations, and none of the browsers interpret it identically. I’ve spent hours writing it just to find out it only works in chrome, then spend a few more hours hunting down and finding work arounds for all of the bugs in each browser’s rendering engine.
It would have probably taken off if there was a way to have wrapped text in the early days.