An individual installing on such a site shouldn't be using a make install target,

Actually, individuals installing on such site only can't use make install if the package comes with hardcoded destination targets. Luckely most packages I grab from the net have been created with metaconf, autoconf or with ExtUtils:: and are coded sainly. That is, no hardcoded values that cannot be overriden.

    ./configure --prefix=/opt/whatever  # Look ma, no /usr/local!
    make
    make install
[download]

works fine in many cases, and in my opinion, every software package should install in similar ways.

Abigail