A New Labour shaped hole
Maybe the obsession with closed source flows from the top of business and government; a culture extremely averse to the risk of trying anything new because they simply don't understand the 'why' - or indeed even try to. The only interest is in what works today, out of the box and without any extra staffing, not what might have better legs in the longer term.
Always easily impressed by big numbers, the New Labouryears also firmly established a culture where 'doing IT' could only be entrusted to large businesses with slick marketing, closed source products and eye-watering support charges.
In a business culture where most jobs entail making the person above you happy without rocking the boat, by any means and at any cost, we probably get what we deserve.