On May 10th (and 11th again) it rained. Why then were the sprinklers on the water the plants? Certainly they'd gotten the water they needed. Why waste water? (some places have droughts!)
Why indeed would B&G water all that green stuff outside below the Mudd ramp during times when it's raining? It's because the rain doesn't fall on that area, which is underneath the scholar study bridges. They have to water fairly routinely to keep the plants and grass alive.
PS: We are talking with B&G to see if there's any way to water that area automatically with water that drains from the roof, as someone suggested in another question.
What about removing the plants?
No way. Everybody loves plants. Keeping them is an Obie kind of thing.