No, logging appenders are plug-in components. If you don't like HTMLLayout, and Google doesn't offer anything you find preferable, you can always write your own.
Just in case you thought there was some "magic" here, I should mention that a straight text appender can be used if you want to. The logfile is simply served up as MIME type text/text in the same way any other text file would be.
Customer surveys are for companies who didn't pay proper attention to begin with.