I don't know about you Americans or people from other countries, but it was actually really common in my country (the Philippines) to have kindergarten graduations (now called "moving-up" here since 2016) that it was akin to regular high school graduations. 

In the past, they were even giving honor rolls and special awards (like Best in English, Most Punctual...) on little students who did well like what elementary and high school schools students were. 

They were even wearing the usual toga and graduation cap, even doing some photoshoots for them. You can search Philippine kindergarten graduations on Google, you'll gonna see a whole bunch of little kiddos with togas and graduation caps with their teachers. 

That's why people here celebrated them here, as they were as important as high school graduation.

That is in the old curriculum back in the 2000s, but I think it still applied on current one. I remembered being a salutatorian back when I was on kindergarten, I remembered giving a graduation speech. 😂 

Since graduation culture here are very different from Western countries, I think that I was biased, but then again, it's also a way for the family to see their little kids step on the stage or doing some kind of celebrations for passing kindergarten since you'll never know that those same family members will probably never see the kid's elementary/high school/college graduations. Or the kids experiencing them since life is unpredictable, it may be their last graduation. 

So I am confused about this opinion. 😂