I suspect this is mostly driven by the economics of the software business. The cost of software is driven by fixed upfront costs. The marginal cost is now pretty close to zero. This means that unless you have some kind of lock in like Photoshop or Office then competitive pressures are going to drive your prices down towards zero.

If you can't make any money selling your product then you will start looking elsewhere. That will include transactions that are against your customers interest like selling their profile to advertisers.