I assume you didn't read the included link. The idea that Chris Pratt could be responsible for Kevin Smith's heart attack is beyond ridiculous.
I'll try to hand it to you slowly:
There are tragedies beyond anyone's control. Thoughts and prayers are all one can offer. They do not offend, unless sarcastic or insincere - and that raises a semantic problem.
There are tragedies which could possibly have been prevented, by unusual foresight or whatever. Thoughts and prayers acknowledging regret do not offend.
There are tragedies which should have been prevented by people who neglected to take ordinary and reasonable preventive measures. The expression of regret here needs to be stronger, and with some kind of active correction of behavior on top of apology, to provide a context for thoughts and prayers offered in public. This situation cannot be repeated very many times, before the apology wears thin and the prayers offend.
And last but not least there are tragedies whose prevention was actively rejected by people, whose prevention was fought, whose occurrence was predicted and nature known in advance, for which innocuous means of prevention had been readied to be deployed only to be spiked and blocked by people who accepted the tragedy as a consequence of their actions.
And here, thoughts and prayers are a tricky thing for those people to announce in public. If one of those people were to get punched in the face for offering thoughts and prayers to the wrong person in that situation, we would regard that as justified, no?
Now we've seen a lot of that last; so much of that bad aji has permeated the public realm that actually offering sincere thoughts and prayers has become difficult, the term loaded with implications. And that's the modern context - everything the modern Republican Party touches turns to shit, basically, even thoughts and prayers.