Yeah, it's not a significant amount of land. But it does seem like these companies prefer to take quality farmland instead of unused land. There's something similar happening near my town, where a company wants to put a big solar array on some prime farmland, and the locals are asking why that spot and not getting an answer. It might save a small amount on development, as farmland is fairly flat and has no trees to remove, but that's miniscule in the overall budget for these things, and rough ground would be much cheaper to buy. But the corporation behind it and the government entities involved are digging in their heels and insisting on using farmland, without any explanation why.
So it does seem like some of the people making these decisions just like the idea of taking farmland out of production for some reason. Maybe they just don't like farmers or modern farming methods. If that's their motive, they may not realize how tiny an effect they're having on the total, because most non-farmers don't really understand how much land is out there.
It's like the people who say Bill Gates is trying to control the food supply because he owns something like 270,000 acres of farmland. Even that just isn't that much, not enough for him to control anything larger than the horseradish market.