Thats not a correct statement. Bitcoin promised, there will be no more than 21 million coins. I suppose You do understand the meaning of this?
They also have made many promises on their product´s characteristics.
Who are 'they'? Bitcoin is not a group of people. Bitcoin cannot have made promises. I doubt you understand the meaning of this.
Sorry, can not answer You at the same rate. As a newbie, my post rate is limited.
"They" are those who decided, there can be 21 million coins. have You asked Youself, why so? Whats the logical/mathematical reason behind it?