This generally is always the same argument, but the fact is one person cant speak for the whole community.
Indeed there are many that wouldn't mind waiting longer for a match, but there are also those console players that want quick games. There are also those on Australian / Asian prime times that dont have the luxury of the wider population EU / US prime times offer. There are countless examples of people who dont want the consequences of expanding BRs or reducing the spread that many dont consider.
People always assume one thing is separate from the other. Reducing the BR spread is exactly the same thing as expanding the BR spread. All you are in effect doing is making the matchmakers options smaller and smaller in terms of the vehicles it can put into a single match and the players it can get into a game.
A BR 15.0 is literally inconceivable right now, as is a 0.7 spread. We just moved to 10.7 and even 11.0 is not even possible at this moment. Let alone 15.0.