I believe that geopolitics and the demography of scholarship have begun to reverse the tide and that the scene will look very different 10-20 years from now. Secondly, I do not believe we should dispense so casually with the merits of linguistic diversity. Quite the contrary, I think we should nourish and accentuate them. Thirdly, I do not think we actually communicate all that well in our lingua franca. Many find it impossible to speak with the nuances and sophistication they intend.
Many speakers are quite difficult for others to comprehend.
Many of our members are consequently silent. We lose participants in our dialogue. We are by no means there. There is no simple solution to this problem. But it is one we can ignore only at our great intellectual peril.