But depending on the game, their web presence might be far more important than a non-tech company. Games need to have a "cool" factor that a non-tech company doesn't have to worry about.
How much money do these hobby/indie game developers have on hand to develop the site? Most build EVERYTHING themselves because they are unable or unwilling to pay others for it. That is the nature of the group of people.
For some, even the payment for a domain name and for hosting is painfully high.
Yes, having a great web site would help their business. Marketing is one of many important factors. Of course, these individuals are having a struggle making the product in the first place. Marketing the product is often an afterthought to them, and an incredibly expensive one at that.
By the very nature of their choices they are unable or unwilling to pay others to develop their web site for them.
Yes, it is true that many indie game developers and hobbyist developers could benefit from professional development of their web site and marketing material. But it is also true that these same individuals are generally unwilling or unable to pay for such a service. Consequently the market is almost nonexistent. Sure there is a potential benefit for customers, but the potential customers are unable or unwilling to pay, making it improbable for a successful service business.