You've misinterpreted what I said completely if you think they should be compelled to do that, rather than for it being a waste of money. One would do something more like A/B testing, anyhow. The fact that GOG.com makes good money off of old games with the DRM removed could be considered evidence. Publishers are certainly free to waste money if they want to, it's simply not good business. Right now, we know it costs money and available evidence indicates that it doesn't help at all.

I don't really think you want them to fail, so I can't see why you would argue that they should continue wasting money?