You should build what they need - though a lot of the problem is that those specifying websites have very little idea about how the web works and what is needed.
Unfortunately this isn't the 60's at Sterling Cooper where you can brain storm an idea like go to "work on an egg" or a "a mars a day helps you work rest and play"
The people that 'ask them to' are bound by an inexorable set of rules appear in the system, for the most part. That system is observable and a little bit predictable, it's just more economic than it is technical, so it's worthwhile for devs to take one step out of their zone sometimes to see how that math works. I don't really think anyone at wired actually wants a slow site or tons of crap ads.
