Having a mobile strategy understates the importance of mobile. It's like having a side dish of steak. It suggests that mobile is one of many important online distribution channels, as opposed to the reality – it is the most important channel, and in fact, making a distinction between the desktop and mobile web is a mistake.
You could imagine a similar debate going on when laptops emerged on the scene in significant numbers in the 1990s. Industry executives were probably saying things like: "They have smaller screens, does software need to be designed differently, should we have a laptop strategy for packaged software, etc." I can remember lugging around my Toshiba with its orange gas-plasma screen.
However, according to Pew, between 2006 and 2011, laptop ownership has gone from 30% to 52%, and desktop ownership has gone from nearly 70% to 59%. Among 18 to 34 year-olds, 70% own a laptop, with only 57% saying they own a desktop. (I think the study lets you answer "yes" to multiple devices.)
What's more, people use these devices interchangeably and expect their files and use cases to work seamless across them. Laptop use became the norm, or at least not the side dish.