I don't know. Players in low Elo have a tendency to not listen unless someone is doing pretty well. I think it would be better to simply play better, personally. They also do not like being told what to do, because they are probably teenagers.
I play mostly among mid to high gold players, and really bad calls don't happen too often. I also play support and a top tank. So if I make a call most of the time people listen, since you can't do a lot of things without a tank in general.
I am very objective oriented, but I usually don't start making calls unless I am playing alright. Again, people have a tendency to not listen unless you are doing OK, although more often then not, most gold players are on the same page with calls.
The problem being with in low Elo and making calls:
- You are in low elo you probably do not make the best decisions
- People you are playing with are also in low elo, they frequently ignore calls or make poor choices
- People tend to not listen in Bronze and Silver AT ALL unless you demonstrate through the score board that you are doing well
When I was climbing my smurf through silver I played a lot of support and I was amazed that players almost NEVER listened to a support's calls because I didn't have kills. The higher you climb the more often the support IS THE shot caller because they have a tendency to have higher map awareness.