I think, it's major problem for the authors who are non-native, poor, having no internal or external funds. To me, research must not be affected by the language barrier.
Mohammed - I agree. It's an age-old issue. However, at the end of the day, we live in a business model world of publishing. The major publishing houses i.e. Elsevier, Wiley, Sage etc are well established and they dictate the agenda. They are usually European, US or Australasian-based - where the language of academia, politics, commerce is often English-language driven. Potentially, this may change with the establishment of stronger global markets i.e. a China-based impact but, until then, we are confined within the 'traditional' market drivers. Against that, as some one that reviews for more than 40 international journals, the market is highly competitive. If I am reviewing a manuscript that clearly conveys its intentions and outcomes to me, versus a manuscript that does not, I'm 'instinctively' going to favour the former - especially where the manuscript submission criteria are clear.
The 'established' markets do have a valid claim to keep things as they are i.e. established regulatory rules around research ethics - and this may be an argument aside of what you are presenting. I often review manuscripts from countries where formal ethical approval is not required. That is a concern - and a disadvantage against those countries that do impose it. It may not simply be 'language' that holds back a manuscript submission - it may be that the 'rules are different'.
I think that the journals that offer this provide a valuable service.
The idea of "international Englishes" means that there is no "correct" or "incorrect." Nevertheless, journals generally expect excellent native speaker-quality English, even when wording something a different way remains perfectly clear.
I think it is a great service, since academic community in many non- English speaking countries, like Croatia, require publishing in high quality journals which are mainly in English. It is not fair that high quality research suffers because of language barrier.