I don't think it's a deliberate ploy: it's a micro-optimization that's localised to the team/company building the API/product, and it improves efficiency at that level.

You can really build and maintain only a single version of your product, forgetting about maintaining old versions. This means pushing backwards compatibility challenges onto your customers (eg. other developers for an API) — the fact that customers have accepted that tells us that the optimization is working, though I am very much not a fan.