I'm just your fellow user, but maybe I could help?
Your criticisms seem to bounce around a little...
Photosynth.net is host to a couple of different types of uploads:
1) original photosynths (created with Photosynth's desktop application for Windows and viewed with either the original Direct3D viewer plugin for IE + Firefox, or Silverlight)
2) stitched panoramas (created with Microsoft ICE, Adobe Photoshop, or Photosynth's mobile pano apps, which are viewed with either the Silverlight viewer or a more primitive CSS3 3D viewer)
3) new synths (the four shapes supported in the Photosynth 2 preview website - walks, spins, walls, and panning synths - and viewed with Photosynth's new WebGL viewer which does use HTML Canvas 3D).