[Solved]-Why are programmatically inserted SVG <tspan> elements not drawn, except with d3.js?-d3.js

You can't use createElement to create SVG elements. SVG elements must be created in the SVG namespace so you need to write

document.createElementNS("http://www.w3.org/2000/svg", "tspan");

There is a jquery plugin which adds functionality to jquery allowing svg elements to be created.