Isn't the answer to that in the comment? You could have used ISO 100, instead of 1250. Or do you just like the noise? Personally, I like grain, but noise doesn't look the same.
Tripods are not allowed. Flash causes a reflection nightmare...so you go with high ISO and make the best of it. The images were processed with a LR preset that adds noise and texture....then some were smoothed back out with a second step. While the photos might not be to everyone's taste...I also know that there is a segment of the photo community that takes the images for what they are....my vision.