Pastor Larry,
I would agree that the rationale you describe may well be the rationale in the minds of the administration. I do not understand how it could be argued that this distinction is valid. There is a difference between the ETS scenario and this accreditation function.
A teacher who goes to an ETS meeting to discuss theological issues is not engaged in a joint ministry with those who compromise the gospel. Compromisers may be present--check that, they are present--but there is not a common agenda of furthering the cause of Christ through cooperative efforts.
This accreditation issue is a cooperative effort in the sense that the educational institutions look at one another's objectives and help them evaluate themselves to determine if they are accomplishing their objectives. (This is the system with the regional agencies, at least. I suppose it is possible that TRACS is different. If TRACS accreditation really accomplishes anything at all, however, I doubt it.) When BJU becomes a part of this process and lends its support to the system, it is affirming that the other accredited institutions are accomplishing their objectives. Within the cooperative structure, BJU is endorsing the educational mission of these institutions. Although I have not researched their missions, it seems self-evident that as religious institutions, some sort of theological purpose is going to be prominent.
I realize that you are not explicitly endorsing this perspective. Perhaps your opinion is similar to mine. My simple point is that BJU has painted themselves into a difficult corner by taking such public stands over the years. When they backtrack without acknowledging past error, they may rightly be accused of inconsistency and/or hypocrisy.
Ironically enough, I know of at least one SBC seminary professor who is contemplating resigning from ETS in light of their failure to defend the faith against the open theism heresy at the last meeting.