I'm aware of Amazon USA's "on demand" service, but this isn't something that Amazon UK have adopted. But those are presumably made "on demand" each time a customer orders one, whereas this current situation looks like the label is making batches of cheaper CD-Rs to send out to the retailers to sell.
I know it costs more money to make pressed CDs, and sometimes the manufacturing plants demand minimum quantities (e.g. 500 pressings at a time), but if a label doesn't think it's cost effective when there's a cheaper CD-R alternative, then I am of a similar opinion in that I don't want to spend my money unless it's a proper CD.
But I think this is the way some items are being produced if they don't expect sufficient sales figures to warrant the cost for a proper CD (or they just want to maximise profits). For example, the film soundtrack market is quite small, and Sony Classical only press some of their titles onto proper CDs for the European market. If you want the same product (which has the same barcode!!) from Amazon USA, it's a CD-R.
If those two albums that I just bought had been advertised as CD-Rs, then I wouldn't have ordered them in the first place. But as I didn't know until I received them, that's why I thought I'd ask on here as I presumed I could get some responses from people who bought these albums when they first came out.