Maybe this is truly an unpopular opinion

It’s not so unpopular as much as rigid or judgmental. I’m not a huge fan of social media, partly because of many attention seeking behaviors at its core. However it has other uses. Posting a “death bed picture” may allow those far away or unaware to know, and see a person in their final moments they couldn’t otherwise- and might mean a lot to them. It makes sure in your circle of loved ones and friends that you don’t forget to notify anyone during a stressful and sometimes chaotic time. It can be a method of dealing with ones grief and isn’t so much different from a public statue or memorial, or even a newspaper obituary. It comes down to individuals. I wouldn’t want such a picture of me posted, for if those I left behind wanted a picture I’d rather be remember as I was when well and not at the end. I wouldn’t begrudge them such a picture though if they felt it would help them. Grief is individual as is coping. In death many seek to remember or be remembered. This is just one method.

So is taking you kids to the hospital for every cough and stomach bug so you can post pitiful pictures online for attention

Depends on the particular social media medium and the people it's intended to reach.

My extended family did this with their mother. All the kids surrounded her and she looked an inch away from death. It was terrible and they do not see the problem with it