The degree advantages you describe are merely a way of redistributing jobs from those without the signal to those with it. No value is created, and some is lost due to the cost of giving people useless educations. The world would be a better place if no one had these useless educations, since employers would no longer be able to discriminate against those lacking the signal.
In any case, it's easy for companies to solve that problem, if they see an inefficiency. If IBM thinks people without degrees are an underutilized/undervalued labor pool, they'll start hiring them. And if the market stops demanding degrees, people will stop getting them. Until then, it looks like a demand-side problem to me.
By the way, a great way to test whether education is human capital formation or signalling is to consider the consequences of failing and forgetting. If you flunked out of college, would you have the same economic outcome as if you passed and then forgot what you learned? If so, then college is human capital, otherwise it is wasteful signalling. (Hat tip: Bryan Caplan.)
If IBM thinks people without degrees are an underutilized/undervalued labor pool, they'll start hiring them.
Unfortunately, in big companies, this is tricky due to agency costs. The hiring agent has different incentives than the company as a whole - if he does something non-standard, he will receive disproportionate blame if it fails, while the company will gain most of the benefits if it succeeds. If he conforms to the standard procedure he can avoid such risks.
This is a fairly well known problem in the economics of large organizations.
FYI, I ignore degrees when I hire. But if I worked at IBM, I might not.
(Not that this makes the situation any less deplorable.)
Essentially, Living Social has done just this. They decided that the talent pool was thin, and the usual means of finding new hires weren't cutting it, so they mixed a bit of unconventional hiring with a dash of unconventional education and came up with the Hungry Academy. It will be interesting to see if this is a continuing trend, though I can't say I exactly relish the idea of corporate sponsored higher education as the new norm.
In fact from what I can find the employment/wage gap between degreed and non-degreed people is actually larger in non-STEM fields. You can get work as a no-degree-having programmer or statistics guru, but if you're not technical, having no degree is a much bigger problem. Among miscellaneous jobs that often advertise that you need a degree: store manager, social worker, high-school teacher, most white-collar clerical positions in large companies, etc.
Sometimes any degree will do. It's not like IBM hiring an office assistant with "B.A./B.S. strongly preferred" is deeply interested in the content of a university literature curriculum, but they use it as a generic screen for some minimum threshold of literacy and maybe diligence. Companies seem to have no way of doing that screening themselves, so they outsource the job to universities, hoping that universities screen out the worst candidates.