I tried to create a plain text log output with this logging.properties file:

handlers= java.util.logging.FileHandler, java.util.logging.ConsoleHandler

.level= INFO

java.util.logging.FileHandler.pattern = c:/temp/logfile.log
java.util.logging.FileHandler.level = INFO
java.util.logging.FileHandler.limit = 50000
java.util.logging.FileHandler.count = 1
java.util.logging.FileHandler.formatter = java.util.logging.SimpleFormatter

java.util.logging.ConsoleHandler.level = INFO
java.util.logging.ConsoleHandler.formatter = java.util.logging.SimpleFormatter

I startup the server with this commandline:
run.bat -c default -Djava.util.logging.config.file=c:/temp/logging.properties

The log file is placed in c:\temp\logfile.log and contains my output, but it is in XML, not in Simple format. Console output is in SimpleFormat as expected.