The problem was he was trying to earn money by means of official resources.
You may have probably heard of a railfan called Syed Zohaibullah. He is a very famous RF, known for his absolutely stunning pics of Konkan Railway. Back in 2018 when he was active he had given a link for a calendar of his containing his pics. I don't know what fee he wanted (if any) but he had to quickly change the post to avoid action from admins. You can see the post at this link: /blog/post/1659212
The...
more... case is mentioned was much milder than the IRTTC one, as in this case Syed Zohaibullah was using his own pics, not someone else's. On other hand, railtracker was using content that is publicly not available, obtained almost certainly from his contacts in IR. Now this itself is quite shady, but rather prevalent too as many (including yours truly) has contacts in IR who give inside scoop routinely. However most of us don't share the info publicly, and for those who do, we rarely put our own watermark on it to pass it off as our own, and definitely don't try to earn ad revenue from it. That thing is liable to be prosecuted, and the site acting as an interface for it makes it liable for getting prosecuted too.
Better to not play with fire in these times.