I assume that you are referring to .7z files?
Well, LZMA compression has been around since 2001, so it's hardly "new". It compresses between 30% and 70% better than zip format (hardly "a few percentage points"), which considering the size of some of the mods around here is of immense help to those that still have 56k modems...and there are a few here. Plus, it's of great benefit to those uploading and hosting the files (bandwidth and so on). There's much more to consider than just whether one user can open it with his comfortable WinZip.
I think Grey Wolves brought Terrapin's site down for a while when it was first released...imagine the impact if it was in zip format?
There's many (free) programmes that open .7z files. It's not that hard to find one AND they'll also open your standard zip files as well (three most popular being IZArc, WinRAR, 7-ZIP).
So, quit ranting, don't knock what you know nothing about and move on...or run an unmodded SH3. The choice is all yours...