Claiming a preference can be fraud, and is often abused, but... in reality, nobody's really checking unless there's a justifiable reason to. Not that I'm endorsing such fraud, and you're right, 51% is usually the safe way to go, but many LLC type setups don't have any easy way to help determine that. It's really quite time consuming and intrusive to determine "control" as the person writing or signing the contract. It's very much based on the assumption of honesty, unless there's some clear indication otherwise (and yes, due diligence is performed and documented, at least to some extent - it isn't just a Google search for "companies that sell widgets near me").
For an extreme example, I won't know that a company is a sweatshop using undocumented drug addicted children if their representations and warranties documentation says they don't.