Комментарии в коде — полезные, бессмысленные, вредные?

/**
 * Always returns true.
 */
public boolean isAvailable() {
    return false;
}

#define false true;

// Magic. Do not touch.


/*
 * You may think you know what the following code does.
 * But you dont. Trust me.
 * Fiddle with it, and youll spend many a sleepless
 * night cursing the moment you thought youd be clever
 * enough to "optimize" the code below.
 * Now close this file and go play with something else.
 */

// If this comment is removed the program will blow up

template<typename T, int N, X = int>
Q_INLINE_TEMPLATE int strToEnum(const T &str, const char *(&strings)[N])
{
  for(int i=0;i<=N;i++) {
    if(QLatin1String(strings[i]) == str)
      return static_cast<X>(i);
  }
  return static_cast<X>(-1);
}

* This source code was highlighted with Source Code Highlighter.

// Magic. Do not touch.
var profilesFound = profiles.GetProfiles(x => (
    x.ApplicationName == applicationName && (
		usernameToMatch == null || x.Username == usernameToMatch
	) && (
		userInactiveSinceDate == null ||
		x.LastActivityDate <= (DateTime)userInactiveSinceDate
	) && (
		(x.IsAnonymous && authenticationOption == ProfileAuthenticationOption.Anonymous)
			||
		(!x.IsAnonymous && authenticationOption == ProfileAuthenticationOption.Authenticated)
	)
));

isCorrectApplication (x) {
	return x.ApplicationName == applicationName;
}

isUsernameMatched (x) {
	return usernameToMatch == null || x.Username == usernameToMatch;
}

isUserActive (x) {
	return userInactiveSinceDate == null ||
		x.LastActivityDate <= (DateTime)userInactiveSinceDate;
}

isAuthenticationAllowed (x) {
	return isAnonymousAuthentication(x) || isProfileAuthentication(x);
}

isAnonymousAuthentication (x) {
	return (x.IsAnonymous && authenticationOption == ProfileAuthenticationOption.Anonymous);
}

isProfileAuthentication (x) {
	return (!x.IsAnonymous && authenticationOption == ProfileAuthenticationOption.Authenticated)   
}

var profilesFound = profiles.GetProfiles(x => (
    isCorrectApplication(x) &&
	isUsernameMatched(x)    &&
	isUserActive(x)         &&
	isAuthenticationAllowed(x) 
));