I suspect this situation may be more symptomatic of trading style rather that purely difficulty in achieving a rigid risk/reward parameter. If one is looking for a large number of trades with small profits and tight stops then it is easy to imagine that achieving a consistent ratio is difficult. Whereas a longer term swing or position type trader may find it much easier to place trades with such fixed ratios.
I would certainly never admit this in public on a site like BP, but, shhhh, I don't actually look at any metrics whatsoever!
I assess my trade entry quality thoroughly and only enter when completely convinced and put my stops wherever it makes best sense (which cannot, by definition, be too out of line with my profit expectation because it wouldn't then be a quality trade).
My money management tends to focus on my progress per week and per month rather than ratios and percentages but that becomes almost intuitively automatic with experience - like adjusting one's speed according to the road conditions........
I am certainly not recommending this approach to anyone but I think it is wise not to place too much rigidity on applying and interpreting ratios and metrics.