Think of it this way.
Iwata was an important man to the entire gaming industry.
It is all but reasonable if other games are used to honor him, as his influence in the gaming world is almost unparalleled and one that deserves respect. Why else did Sony send condolences?
Not criticizing your opinion, just offering a different outlook on it,
I understand that, and I did consider that viewpoint. Iwata has had a huuuuuge impact on the video game industry. And he's instrumental to Smash Bros. which is why I've been upset all day.
This is the first celebrity death that I've ever been sad about. However, to me, it's like this scenario: Henry Ford died. Then instead of riding/ posting about a Ford car, you go and say, "Thank Ford for the Toyota!" Sure Ford impacted Toyota, but if you want to really, really honor his memory you should focus on his own accomplishments. Sorry for the crappy analogy.
For me, the best thing that people can do
is go and read about Iwata's life. Go play his games.
Donate to cancer research. Posting memes on the Internet won't bring you really closer to the work and the impact that he's done. In my opinion, it's superficial. Again, I'm not trying to come off as a jerk, just trying to explain my thoughts. I can totally understand why people will not like what I said, and I'm not expecting other people to "accept" it.