1500mmania - yes they do. We did it for ten months, not six, on the recommendation of our paediatrician. Can honestly say it didn't bother me at all. Although that's because the family history means I wouldn't contemplate anything else so for me it was just what we did.
Whooah in all honesty I don't know - my DD has never napped in a cot in the day either. I just know the recommendations. She had a crib downstairs until she was too big for it, from then onwards she naps in a lie flat pushchair. I did try to get her to nap in her cot more than once, whilst I was upstairs, and she wasn't having any of it.
Until 10 months she was wired to a monitor every time she slept - every nap, every night, so a sling was never going to be an option regardless of what the research says. As we didn't have a sling there was no opportunity for her to "only" sleep in one. From birth her options were pram when out, crib or cot. We couldn't use anything else, so she either slept in one of those or we walked the floor until she was far enough gone to be put down. As she didn't know any different there wasn't anything different for her to express a preference for IYSWIM?
*IveBeenGood" - babies do love slings, and they do have benefits, but research has shown that anything other than a flat shape can restrict air flow into the lungs. Babies love slings because it is reminiscent of being cocooned in the womb, being cradled comforts them. But in the womb they didn't need to breathe. That said very few babies have problems, but some do, babies have died from restricted air intake whilst sitting in carseats. The deaths of some babies have been linked to overheating due to having their heads covered and also from not lying flat - and noone knows who those few might be or why those particular children were more at risk than others who are absolutely fine in slings and carseats and anywhere else.
FWIW the babies who died in our family died in their cots over night, so I am in no way saying that any one thing is a guarantee, rather that I choose to stick to the recommendations and guidelines because they are supported by research. If I didn't believe in that research and the results there would have been no point in us spending an hour a day completing research paperwork, and our family has done this with every baby for two generations now, for ourselves definitely - but also to further the study into how to prevent other families going through the same thing.
At the end of the day we are all trying to do what is best for us and our children, and we don't have to agree, nor do people have to stick to guidelines, because that is just what they are. I do think that more work should be done to make people aware of the guidelines, and the research that informs them though, because I believe people need to know the information to be able to make an informed decision.
I do hope I haven't upset anyone, that wasn't my intention at all.