It has been since 1994 that a single-car team owner has won a championship. If we allowed the current trend to keep going, down the road 10 years we might be saying that it has been since 2005 than a car owner with two teams has won a title.
An argument can be made either way, but as time goes on a stronger argument may be that an owner with multiple teams contributes to the roadblocks. That's an issue NASCAR has to take a hard look at.