Speculation: Scientific literature may be dominated by American English even among those not of American origin. It may be due to the worldwide commercialism of American culture over British culture. An example of such might be the increase in hyperbole, a very American thing (adopted in Britain in dramatic form in their media) over the past 50 years or so. a potential sign of this process, if it does, indeed exist, which it may not at all. Again: Speculation.