Your argument here is basically just "I already know Markdown". Sure, the Markdown image syntax is similar to its hyperlink syntax, so if you know the hyperlink syntax then the image syntax is easy, but the same argument works for reST but even better, the image syntax is the same as any other directive, so if you know how to write a directive then you know how to write an image.

No, basically it's "I can remember markdown easier because it's simpler"