I also "saw the light" with regard to the difficulties of being a parent when I took a 2 month old and a 16 month old on an 11 hour LHR-LAX, and back again. But I didn't see it completely...
I don't doubt that there are many different points of view about the wisdom of securing "infants" in a particular way, as the rules require. However, the fact remains that people who are paid to know these things have determined that the existing procedures are the safest at this time for both my kids and surrounding passengers. Travelling as a passenger, I have less detailed knowledge about Safety procedures than the Safety authorities, and therefore, like it or not, I defer to their knowledge and experience. Not to do so would be unwise, and might put my childrens lives at risk, or other passengers: It might not, of course, but I have absolutely no way of knowing for sure! This is also the mindset that made me decide to vaccinate them using MMR vaccine, and also that makes me insist that they wear seat belts in the car, and incidentally, makes me turn off my mobile phone in flight. The prevailing wisdom is that this is the safest practise, and I have insufficient knowledge to know better. When working as crew, I take the same view.
I'd also point out that if an individual chooses to interpret one particular instruction from the crew (and therefore the delegated instruction from the commander) according to their own assesment of the situation, a precedent is being established. What other instructions from the crew might that passenger wish to interpret as being a suggestion rather than an instruction? The same passenger might logically conclude that provided they were careful with the ashes and stub, a quick cigarette in the toilet is acceptable. Or that, while the aircraft is paused on the taxiway, it is an acceptable risk for them to unpack the overhead compartment for their bags. Extreme examples? Maybe, but all round I find it easier, and usually wiser to obey the rules.