People who were running their sites with static web pages are excited to run their sites with dynamic components in it and a database. They could go for joomla if they want a content management system, or they could go for OS commerce or anything thats like that if they need a shopping cart. But people fascinate themselves by developing a site for themselves. And when they do such things without any experience, they do everything wrong. They dont give an index key in the database, and this would mean that comparing every data would consume a lot of time, and a lot of server resources.

When we admins find that a particular site is overloading the database, we take the appropriate action, and negotiating with the client that though his site is small, the processing resources that its consuming is high, they will not understand.

It is better not to worry about such programmers. And always maintain a high price for your hosting and give people who know what is what some quality support, and make sure that they dont do bullshit on your servers like this.