The most recent Military Times survey reported 58% of military respondents oppose a DADT policy change, and that was strong enough an issue that 10 percent said they would leave the military while 14% would consider terminating their careers after serving. Although it is true that a modest percentage of mainly younger generation soldiers might be able to serve without issue beside gays, it is also obvious that it would cause frictions with those significant numbers of others that would predictably cause distractions and lack of cohesion. Especially during this war time.
As long as homosexuals keep their sexual preferences secret, there are cannot be problems else it would not be secret. If homosexuals are allowed to be open without restrictions, morale problems will be certain to arise with a significant number of other soldiers. Soldiers often share very close quarters that are certain to make some other soldiers uncomfortable by invading their sexual privacy. If females and males dressed, showered, berthed, roomed together one could predict similar problems would be certain to occur. The solution may be to allow homosexuals in the military but never in situations where they cannot be isolated in the same way heterosexual females and males are currently isolated. Thus dressing/showering/berthing/room sharing etc would need to be separated into four areas.
Additionally Don't Ask Don't Tell protects gays by keeping their sexual orientation secret from other servicemen, some of which otherwise predictably would act negatively against them. Further if gays are allowed to act naturally gay-like, that is certain to provoke some into violence. As I have related earlier, it is not merely a matter of re-educating such tendencies via gay sensitivity training because for many in heterosexual dominant American culture, homosexuality is considered a serious taboo and unacceptable behavior. Something mere political legislation or court directives cannot and will not change. Simply a fact. Christian religions will always be allowed those historic moral opinions that cannot be legislated or court ordered otherwise.