>> the installations seem to be of little use or value.
Not quite true. Ground installations will never take extra minerals for repair (spaceborne modules on civilian ships could be damaged, and thus require repair work), and do produce tax income, which the modules don't. You can also build them with construction factories, rather than generally more limited shipyard space, and you can build them with less research investment and thus get them operating more quickly, so they do have some niche uses.
On the whole though, yes, installations are generally not as useful or widespread. I, and probably most players I suspect, only build a few at the start of a game, and then rely on terraforming ships when they become available, and any extra installations dug out of ruins or captured from NPRs. The 2.0 version will certainly be more interesting though, as they will become cheaper than modules, and easier to use, with the lower worker requirements and size, so there will be a genuine choice to be made over which you favour, especially for games that have a conventional start, and/or lowered research rates