For example, somebody might be selling land (because they know such issues will get worse in the future), and if farming will be prohibited, they will get a worse price for the land. Hence best to deny, or at least question the existence of soil problems.
If these entities have a lot of money, they can create their own journals and publish science that says "there is no problem with the soil". They can also bribe scientists and reviewers with high status. They can lobby politicians. And lastly, the media can be caught too, you have to frame it as a political issue so you have 50% of the media in your pocket.
Now look at it from a politician's point of view. If you really get the signal that it's not a real problem, then it certainly doesn't make sense to spend resources on it.