SGOTM is a competition where the Team with the best test game makers and adequate players win.
Test Game Building, the Most Important Skill in Winning SGOTM
I think these statements are offensive to all teams, not just the winners . What you've done is discount the skill and experience of all players and made the claim that WB skills are more important than Civ skills. That's just crazy talk.
No one has made the claim that test games are not helpful. Obviously, they are useful or else no one would use them. To add to what kcd said, a test game aids with micromanagement decisions. With enough time, a team could come up with perfect MM to implement their strategy. But, what if said strategy is not good? The team will have perfectly implemented a poor strategy, which will Not lead to the gold.
Did a test game tell team OSS to use espionage to the level it did last game? No, it was mainly due to LC's experience and out-of-the-box thinking to suggest a strategy that would work well in that game. Did a test game tell the Ducks to go all out for the Great Lighthouse? No, it was the collective experience of the team that told them that the reward of getting it was worth the risk (which they assessed to be small based on what was happening in their game). Did a test game tell Fifth Element to found Mining Inc? No, it was the teams' experience that told them that Mining Inc. is a winning strategy for Space Colony games. A perfect test game (i.e. the actual World Builder file) would never "lead" you to these strategies. Only skill and experience can do that.
When you get down to it, test games are a tool, just like spread sheets, pen and paper, etc. You don't need to be a World Builder wizard to put together a basic test game of the starting area, which is all you really need to optimize the starting tactical moves (which again are arrived at based on skill and experience).
In the end, the teams with the better strategies will always rise to the top. Test games deal with tactics and MM decisions, they do not define the strategy. Things that are way more important than test games include skill level, experience, team dynamics/team chemistry and risk management (often called luck).
EDIT: Test games do not tell you which techs to research, when and where to settle your cities, how to manage the economy, which civics to run, how and when to use the whip, which infrastructure to build, where to build the National Wonders, which World Wonders to target, when to attack, how big your army should be, how to trade techs, etc, etc, etc. Wouldn't you say that these things have a bigger impact on success than any tool that could be used?