I think there are several factors contributing to this widening gap between employer expectations and student skills. Although academia has it's (many) flaws, I think in this case the problem is more in the companies.
Recruiting budgets are low, and they are managed so they maximize the short term impact: bringing good enough people as fast as it's needed.
There are (sadly very few) companies that see this recruiting and employer branding activity from a much more holistic perspective. These companies are willing to invest in the future, creating meaningful internship programs, collaborating actively with schools, having interaction with the students in the most varied ways.
Investing in this I believe creates a very clear image of the company in the mind of students, they understand what to expect while working in that company and what skills to build upon to be a great candidate for a job.
Given that more companies would do this, students will have a better picture of what's expected of them, would figure out what would they like to do in their future career, get intrinsic motivation to learn more, experiment and improve and actively prepare themselves for employment.
If you associate this intrinsic motivation in students who have figured out what they want and know what they need to get there, with a flexible, project based approach to education... the world would be a better place.