No, there is no lack of understanding about the importance of promoting sleep. To suggest that somehow medical professionals haven't got round to working out that there are benefits to having a good sleep is, to be frank, completely ridiculous and quite insulting.
A very specific example would be the importance of sleep in relation to delirium in elderly patients. This is taken very seriously.
In a wider sense, hospital staff will try to establish a reasonable environment for sleep. There is a need to be realistic though, and accept that (for many many reason not readily apparent to the lay person) it just isn't always possible to remove all the factors that disturb sleep.
Most patients on a ward are in multi patient bays. If a patient is unwell medical staff will probably have to; talk out loud, turn on a light, move some kit around, walk in/out of the bay... and so on. This would certainly wake me up. There's just very little can be done about it. Clinical need top trumps comfort.
There will of course be room for improvement, and some staff will be forgetful of the need to be mindful of quiet hours (it's very easy to forget it's 'night time' when your brain is in 'at work' mode).
So, a more balanced summary would be: "Medical professionals try to promote a good sleeping environment, but the very nature of a hospital makes this a challenge. However, there is always room for improvement and many local issues can be solved via improved patient-staff communication". Doesn't make for such a clickbaity whinge blog though when you phrase it this way.