The problem with your thinking Oldie is that all the TF2 maps are designed to more or less require multiple types of units working together to be effective. I have yet to see any map where a single unit has complete control over the entire map. Just as the name implies, Team Fortress 2 is all about team tactics.
The scout works well as a fast attacker that rushes in after heavier units bust through defenses. While the forward attackers are breaking down defenses, your job should be to watch for enemies flanking the position, alerting the forward attackers, and doing as much as you can to protect them while they open up opportunities for you to achieve objectives.
In my opinion, a good Scout can be an invaluable addition to a team on any map. Scouts are essential on CTF maps as they can quickly break the intel out and capture it before any enemy counters can build force. On CP maps, Scouts have great value as they can break through the open defenses, quickly jump on the point, and capture it twice as fast as any other single unit. On attack/defend maps, the Scout has great utility on both the offensive and defensive teams. On the attacking team, Scouts do a great job of flanking around building offenses and distracting them from building ubers or staying together as a cohesive unit. On the defending team, Scouts can quickly explore the area looking for possible trouble spots while also distracting the defense.