Although it is unfair to generalize this to all Indian software companies, unfortunately, it is mostly true. In my opinion the reason is mostly one of these three:
1) Some Indian companies, look to cash in the price arbitrage, and have a short term view (3 - 5 years). So they bid for projects, where they have very little expertise and experience. (In India, there is a huge market for sub-sub-contracting. Companies, win projects and then look for people with expertise to actually execute them. (Personally I have been asked to consult so many times)).
2) Education in general is in shambles and especially C.S. education. Also education is (unfortunately) a business. For example the latest fad is to start Android development classes. So many are coming up. (but most of them don't have good tutors. (Again, personally I am asked to come in as "Industry Expert"). Students join these classes and 3 / 6 months later they consider themselves qualified. (when in reality they know so little).
3) Most students (regardless of aptitude to software development) take C.S. is college because of better job prospects. Obviously they cannot be good engineers. There is such a shortage of engineers, that invariably such people do get hired (which feeds the cycle) and lowers quality of output.
About Me: I am an Indian software developer and founder of a software development shop.