If you couldn't recon it would just be a capfest. In a 1 on 1 situation with the flags, whoever is winning will just go hide somewhere near mid, so when his team revives he rushes in, forcing the other guy to sit on their 1 or rush out before the revives. Having this would force more camping and slower pace gameplay aswell as people to hide in stupid spots. [which already happens but with recon you can find them]
Having recon you use strategy. If you have numbers on the opponents and you have a guy dead reconning where they are, you can set up an attack to grab based on the what the opponent is doing. You still think with recon, infact you probably think more. With recon you know where the opponent is going, so you think of the best way to get him or if you have a chance to cap/grab. Without recon would be more sit on flag spraying everywhere. Then all these 10 path maps you have to think... hmmm which outta these 10 paths would he have taken? How does that help your thinking? With recon you know the path so you think.. Whats the best way to cut him off before he can cap?
With no recon, the maps chosen would be horrible gameplay. Pbcup_pforest wouldn't get played or carpathian due to the paths and teamwork needed. It would be maps like blitz and airtime. If you watch good clans play, they all use teamwork. They have strategy in their gameplay. They set up where to go, they take advantage of when they have the man up.
The arguement against could be: People just run to grab and if they die they just tell their team where the opponents are. But if he does that, the team is down a player, so the opponents have the upper hand. I can garantee most teams would love to start every round man up. Cause then you can take advantage of it and assume they wouldnt rush your base [unless your playing hyphy
].