Looking on the internet deeply has found these results:

wonder why that is is the most popular phrase on the web.

wonder why is that 1329,000 results on the web	wonder why that is 1380,000 results on the web More popular!
Some examples and use cases from the internet:	Some examples and use cases from the internet:
It doesn't look like this phrase is very popular! The search could not find any examples on the internet.	Ever wonder why that is, Sammy?

wonder why is that

1329,000 results on the web

wonder why that is

1380,000 results on the web

More popular!

It doesn't look like this phrase is very popular! The search could not find any examples on the internet.