Blimey, talk about shooting the messenger!
From what I've read one of the key points these researchers have made (and that the National Literacy Trust, or whatever it's called, have been making for years) is that there ought to be more affordable rear-facing pushchairs, like there used to be. So saying their research is pointless because rear-facing pushchairs are expensive makes no sense - the point that they're expensive is known to the researchers, that's something they think should be changed.
I don't understand why people are so cross about the research being done. Sure the effect may be small, but wouldn't you rather know about it than not? Even if all it does is highlight the issues of communication and reassurance, surely that's a good thing! Parents who know about this and have babies in forward-facing pushchairs (I've had mine both ways, personally) now just have an extra reason to make the effort to keep talking to them, crouching down to remind them they're there and so on, and also to e.g. turn the buggy away or stop and crouch down if there's a particularly noisy group of people or dogs coming up ahead. Without research like this we might think none of those things really made much difference and not do them quite as much (even if we still did them sometimes) - now we know they can make a difference even if it's small, surely that's a useful thing to know? Why shoot the messenger?
This is like breastfeeding issue isn't it? Sod the parents coming after us, or parents who still have this decision to make, and their right to accurate information - the important thing is not to say anything that might make us existing parents uncomfortable in the slightest about things we've done and can't now change, however innocently and well-meaningly we did them at the time.