To my eyes, it seems ugly without grills because it looks like something is missing.... like an incomplete boombox. Just like if a badge, knob or label is missing, it will bug me to no end. But probably the biggest reason I will never remove grills for looks is because over the decades, I have seen so many nice speakers have their cones or dustcaps damaged. If you've seen as many poked in dustcaps, whether deliberately by playful children who can quickly destroy expensive 6-way speaker systems in seconds, or by accident, or from pets, you might understand this fear for me of leaving off grills.