Agreed, but not so fast, friend...would never tell a player "that's all you're gonna get." In competitive soccer, playing time is earned--through practice, and through the minutes you do get on the field.
I would also never tell my team "everyone is going to get significant playing time in every game" regardless of disparity of skill level and whether we are in a one-sided matchup or dogfight for a win in a region match. Putting a player who is not quite ready for the level of competition at hand into a match at a crucial point--especially as a defender--is not always doing them a favor. However, getting them in for a few minutes against a quality side so that they can get a sense of the level of play and what they need to improve on to meet that need--that, too, can be developmental, without putting the team's efforts at risk.
Putting a player in for significant time only against weaker opponents gives them lots of field time, but not necessarily a sense of what it takes to develop into a starter; I've seen players get five minutes on the field under hard pressure, though, and come out to the next practice with a new resolve.
I've always felt that in practice, a coach's first duty is to develop players. In a game, the coach's first duty is to the success of the TEAM. That means making sure the personnel on the field are the ones best suited to the success of the team--but it also means taking whatever opportunities you can--WITHOUT harming the success of the team--to give developing players enough experience to see what it takes to BECOME one of those players best suited to the success of the team. Maybe that's playing the whole 80 against an opponent that challenges but doesn't overwhelm their particular skill level, and maybe it's five minutes against an opponent that runs circles around them so they get a sense of where they are...the circumstances have do dictate the balance between developing the individual player and developing the success of the entire team.
