I am doing an archive with xcodebuild (xcode 5) through the command line as so:
xcodebuild -project MyProject.xcodeproj -scheme MyScheme -sdk iphoneos7.0 -confi
Check again build settings. Take a look at Debug Information Format, it should have DWARF with dSYM file
For futher information take a look OS X Man Pages xcodebuild and Xcode Build Setting Reference
xcodebuild -project MyProject.xcodeproj -scheme MyScheme -sdk iphoneos7.0 -configuration Release archive CODE_SIGN_IDENTITY="iPhone Distribution: My ID" -archivePath archive/MyArchive.xcarchive -xcconfig Config/MyReleaseConfig.xcconfig CONFIGURATION_BUILD_DIR=$SRCROOT/build/$CONFIGURATION$EFFECTIVE_PLATFORM_NAME
what's your config about DEBUG_INFORMATION_FORMAT in MyReleaseConfig.xcconfig?