Contador estático da Thread Factory

Há algum motivo especial pelo qual não sincronizamos de alguma forma (synchronized, AtomicInteger, etc) o acesso ao:

private static int numero = 1;

da nossa FabricaDeThreads?

public class FabricaDeThreads implements ThreadFactory {

    private static int numero = 1;

    @Override
    public Thread newThread(Runnable r) {

        Thread thread = new Thread(r, "Thread Servidor Tarefas " + numero);

        numero++;

        thread.setUncaughtExceptionHandler(new TratadorDeExcecao());

        return thread;
    }
}

Sendo que o próprio DefaultThreadFactory do Java assim o faz:

private static class DefaultThreadFactory implements ThreadFactory {
        private static final AtomicInteger poolNumber = new AtomicInteger(1);
        private final ThreadGroup group;
        private final AtomicInteger threadNumber = new AtomicInteger(1);
        private final String namePrefix;

        DefaultThreadFactory() {
            SecurityManager s = System.getSecurityManager();
            group = (s != null) ? s.getThreadGroup() :
                                  Thread.currentThread().getThreadGroup();
            namePrefix = "pool-" +
                          poolNumber.getAndIncrement() +
                         "-thread-";
        }

        public Thread newThread(Runnable r) {
            Thread t = new Thread(group, r,
                                  namePrefix + threadNumber.getAndIncrement(),
                                  0);
            if (t.isDaemon())
                t.setDaemon(false);
            if (t.getPriority() != Thread.NORM_PRIORITY)
                t.setPriority(Thread.NORM_PRIORITY);
            return t;
        }
    }

Obrigado.