Do you mean the A-level/GCSE subject, or as a degree?
For the former, it's a perfectly acceptable subject. It has the right balance of interdisciplinary and breadth to foster independent investigations into various aspects of it in further depth from the student. It can be a useful starting point for students interested in many areas - particularly for example, earth sciences, which doesn't have an associated A-level (at least, not commonly available/accepted - A-level Geology is pretty rare and not usually considered as a core science by universities, although it would also be suitable with other sciences in preparing for this route, certainly). Geography with e.g. Maths and Biology/Chemistry/Physics would be a reasonable background for pursuing this direction. It also complements subjects such as Economics, Politics, and History well.
In the case of it as a degree subject, this nature of the subject described above is the issue most have. As you progress through academia, in general the expectation is you need to continually narrow your focus into more specific areas of study and research. Geography at degree level suffers an identity crisis; is it a scientific subject analysing the natural world? Or is it a social science considering aspects of development and demography? Is it something else entirely, a technological vocation focusing on specific computational methods of storing and presenting information about the world we live in?
Therein lies the problem - it's trying to be all of those things, but there are other degrees which train students in much greater breadth and depth in those specific areas. Earth Sciences, Sociology, Economics, Computer Science, Environmental Engineering, etc, all consider these issues, but build up a incredibly strong foundation in the core skills of the discipline allowing their graduates to pursue their interests in this area and use skills from a number of perspectives within that discipline. Geography just...has a mishmash of bits and pieces of all of those mashed together in the most vaguely coherent way.
It's a "nothing" degree. It prepares you for no specific role, no particular area of academic research, no specific skills beyond generic transferable skills developed on any degree. It's the kind of degree people do when they're (upper) middle class and plan on going to work in media or similar afterwards, for whom a degree is just a tick box that they already know they're going to achieve and will have no financial or other considerations to make in pursuing one.