To me the motivation behind this decision is quite transparent: the guy who is behind original Markdown syntax has blamed himself for choosing the unreadable format to insert images (cannot find the link to prove this right now). So having Obsidian support both standard markdown for images as well as simplified notation is a good thing, IMO.
Also, you don’t seem to be worried about “incompatible” links format in Obsidian which had similar rationale, I guess.
These don’t appear critical to me. Should something happen to Obsidian, we can use any text editor and simple RegEx to replace all those “incompatible” pieces of syntax with “more compatible” ones.