Mockery is immoral since it only serves the mocker.
Not when Mockery is effective.
Remember, most of this is a matter of marketing/advertising. Free publicity can be very effective, and sometimes mockery can achieve that.
PETA, famous for publicity stunts, continues to do them because despite negative perceptions by many, market research shows that it works (it's the most efficient way, dollar for dollar, of getting a message out).
Whether you like it or not, controversy stirs up very valuable publicity.
You should know the old adage "There's no such thing as bad press". There might be bad press somewhere, but something which is merely controversial in this sense has many more advantages than disadvantages in most cases.
Those who are moral seek effective methods of conveying a message,
Sure, but you haven't demonstrated that mockery is not effective. It doesn't get the message across well to the person being mocked, but because it gets free publicity, it does get the message out to third parties very effectively.
You're being very presumptuous here. You need to study marketing to even begin to analyze this kind of behavior in concrete terms of efficacy in a media environment.
Yes, he is promoting secularism, but then so have I. It's a difference in tactics. Dr. Tyson also promotes secularism and I support his methods as being not only superior than Dawkins' but also much less self-serving.
They may or may not be less self-serving; we can't know the minds (or bank accounts) of Dawkins or Tyson in this case.
The method may be superior in getting the message out to some people, but may be inferior in getting it out to others. Different audiences, different tactics. The methods are different, but it has not been demonstrated that either is necessarily inferior.
Dr. Tyson does seem to be doing a very good job, though. He does come across as more likeable to most.
I'm not saying I favor Dawkins or Tyson, but you're making unwarranted conclusions here from a position of ignorance of the marketing aspects of the various tactics.