You can do infinitely scrolling backgrounds without this, e.g. in the autorunner template. Also Sprites are better for tilesets - if you have crashes using them, you should report it as bugs and we can look in to fixing it. C2's spritesheeting on export will make them in to a few large images anyway, so you still get the fast download and low memory usage at runtime.
The main reason it's not supported is while it's easy in WebGL, the canvas2D API for tiling images is completely flat out bonkers. I have no idea why they designed it the way they did, but it was a struggle just to get it working with scrolling, and a huge PITA to get it working with rotating layers, so I dread to think of wrestling it in to doing offsets. In the mean time there are workarounds, such as using masking layers or just sprites for tiles.