I think what people are telling you is to first devote yourself to becoming a highly skilled diver. The Divemaster course does not do that. It focuses on being part of a professional team, including helping with students.
There are some who say just "dive! dive! dive!" I am not of that opinion, either. I have seen too many divers with very poor skills who use the dive! dive! dive! philosophy to get those poor skills fully entrenched in their systems. What I think you should do is find a really good instructor--and take your time looking--who can teach you some good, sound diving techniques in a few simple classes--maybe only one really good one. Then make sure you use what you learn while you pile on the dive experiences. When looking for an instructor, I suggest you find one who regularly does more advanced diving, someone who does not just swim along the pretty reefs, where buoyancy and trim are not all that important.
There are some who say just "dive! dive! dive!" I am not of that opinion, either. I have seen too many divers with very poor skills who use the dive! dive! dive! philosophy to get those poor skills fully entrenched in their systems. What I think you should do is find a really good instructor--and take your time looking--who can teach you some good, sound diving techniques in a few simple classes--maybe only one really good one. Then make sure you use what you learn while you pile on the dive experiences. When looking for an instructor, I suggest you find one who regularly does more advanced diving, someone who does not just swim along the pretty reefs, where buoyancy and trim are not all that important.