BB, you have posted your photograph in much the same way as I would do, sized at 1024 px wide. Your image has a total file size of about 777 kB and has loaded quickly. I have been posting images with file sizes of about 250 kB and don't think that there is any significant difference in the quality as seen over the web.
I use the "save for web" facility in Photoshop which automatically reduces the image to 72 ppi and then gives an option to resize the image to the 1024 px width and adjust the image quality which will alter the file size to my usual 250 kB or there abouts. These files are often from camera images of 40-50 MB and this resizing process can be done manually if the photo editor being used doesn't contain an equivalent to the Photoshop "save for web" facility.
The images posing problems that I have recently seen didn't seem to contain the file size of the image in properties when I examined them, unlike the image from BB posted above.
Is the problem due to the fact that a number of people do not understand that image quality on the web is limited and are posting large files in the belief that their image will benefit from that larger size, the truth is it will not, all that will happen is that download times are increased. On super fast fibre optic broadband this increased time is likely to be insignificant, if a small image downloads in say 2 seconds, then a download time of say 10 times that will still only be 20 seconds, however for those of use using old fashioned copper connections a download time of that same small image might be say 20 seconds, 10 times that becomes 200 seconds, in other words over 3 minutes, then you begin to notice how significant that is.
The size of file initially produced by the camera has no impact on this issue, unless the person concerned doesn't understand the necessity to resize that file to take account of the limitations of the internet, particularly for those of us who either don't have access to super fast connections, or are unwilling to pay the cost of such connections.
Barrie