"major motive" is correct and usable in written English.
You can use it to describe a primary influence or reason why someone does something, typically used in a context of strong emotions or motivation. For example, "Revenge was their major motive for the act of sabotage."
Similar results were found among British university students, where cigarette smoking was a major motive for WP smoking 32 and among US students, where the majority of WP smokers were also cigarette smokers.
It thus became an instrument of political centralization, and it provided the major motive for modernization.
But, ultimately, the major motive is to make art a form of sport.
The "booty" factor was indeed a major motive for much ancient warfare, and this war was no exception.
It can also be argued that interest in the character of one's own being has been a major motive of philosophical inquiry as a whole.
The major motive is financial: shifting the last paper checks to direct deposit or a debit card (only 2 percent of recipients go that route) will save $1 billion over the next decade, the department estimates.
When asked to list major motives for watching television, a substantial number of individuals refer to the ability of the medium to help them learn about and keep up with the world around them.
'There were two major motives.
For governments, one of the major motives for using information and communication technologies (ICT) at all is to increase transparency.
Disincentives on car use, parking incentives on carpooling, and comfort and convenience attributes are major motives for travelers to use carpooling service.
While these efforts to control the drug-resistance to Gleevec may be encouraging, major motives behind such efforts, seem economical [5].
