Preparing for GATE do help in other exams which are given here
Most people after Masters in IITs/NITs go for job and only few (less than 20%) go for Ph.D. So, don't think GATE is meant for teachers
Even after Ph.D. not everyone becomes a faculty. There are research jobs in companies like IBM-IRL, Microsoft Research, Xerox Research and many others
Even if you want to do MS abroad preparing for GATE does no harm. It'll surely help you for MS as GATE is checking just your basics in Computer Science subjects
Preparing for GATE do help in other exams which are given here
Most people after Masters in IITs/NITs go for job and only few (less than 20%) go for Ph.D. So, don't think GATE is meant for teachers
Even after Ph.D. not everyone becomes a faculty. There are research jobs in companies like IBM-IRL, Microsoft Research, Xerox Research and many others
Even if you want to do MS abroad preparing for GATE does no harm. It'll surely help you for MS as GATE is checking just your basics in Computer Science subjects