The Wireless Application Protocol is designed first and foremost for resource-constrained devices. The displays are tiny. Bandwidth is puny.
Processors are slow and memory is scarce.
Battery power is precious. Mobility is the only resource available in abundance. These devices go anywhere, their batteries last for days, and they slip into a shirt pocket without ruining the line of a business suit. With such a target market in mind, nothing in the WAP spec forces device manufacturers to implement features that add cost and do not deliver value to their target customers. Developers need to know not only how the different aspects of the WAP standard work, they need to understand the profile of the devices used to access their applications.