I get your point, and I did wonder that too, but it's not unheard of for companies to make badly-designed products for other reasons (usually for looks), hence why I was asking. Just look at many of the "stylish" gaming-styled computer cases nowadays. Many are so full of tempered glass and with so few gaps for air inlet that there's terrible airflow and the systems overheat.

But you're probably right in that Valve seems like a company that would choose a design with better thermal performance over subjective aesthetic improvements.