Well i can't explain everything in english, but main reasons is that it's make output binary more huge (yapb2 with debug build = 1.02Mb, yapb2 with debug build + STL = 1.37Mb, on VC++Pro

, staticly linked against STL because "new" versions of VC uses non-standard dll binaries (msvcp80.dll), sometimes my friends has some errors using soft on different linux distros, with segmentation faults on libstdc++.so, and i don't like to code with STL, code style, tons of template parametrs, and all those allocators and stuff.
It's just my opinion...
