'it's fine, it's normal in lots of cultures'
Over the last few years I've seen waves of this judgmental martyrship on the sleep board on Mumsnet. Including from the OP
I hate it and am vocal in countering it when I see things like:
"hourly wake ups all night, every night. Completely normal..."
"multiple night feeds at 9 months old, all fine, all normal, to be expected..."
"still breastfeeding multiple times through the night at 18 months, you are rediculius to expect anything else"
These things are just as unhelpful as things like "leave baby to cry, it's the only way". Or "just put your baby down and leave" and completely fail to recognise the many ways to approach sleep with a no-crying or minimal-crying parenting style that do not mean being a martyr, compulsory cosleeping and multiple night feeds for extended periods.
I've worked bloody hard to establish his current good sleep habits
I know how hard you worked Notta 
Both nature and nurture matter when it comes to sleep.
I also don't like reading things like: "how good a sleeper DD is now is that it's nothing I did". Because again, it perpetuates a false ideal and isn't supportive or helpful in the real world. What Sleepthief84 did was (either consciously or by fluke) matched her parenting style towards sleep to her DDs preference. That does not mean doing nothing and it's unfair in mums who end up all mixed-up with sleep specifically because they do nothing to help their child's sleep.
Parents get into a mess when their Gina Ford type baby who just wants to be left alone, is faffed and fussed over. Or when the needy baby who prefers closeness is just put down and left alone. And everything in between.
It's not about doing nothing. It's about recognising, properly recognising rather than just taking the path of least resistance, what suits baby best placing that at the centre of your parenting style.