Agreed. You can do so much with them too. Distance, speed, mixing it up, lower or upper body bias, etc. it's not a fad, doesn't require upgraded membership, a specialist gym, a trainer, so would gyms push them?
Good time btw. I like 500m bursts. Under 1:40, but keeping the strokes per min as low as possible, aiming for 20-25. 45 second max break, repeat, repeat, etc.