Change rule - Indented Code Blocks can interrupt a paragraph

[namse]

http://spec.commonmark.org/0.27/#indented-code-blocks

An indented code block cannot interrupt a paragraph, so there must be a blank line between a paragraph and a following indented code block. (A blank line is not needed, however, between a code block and a following paragraph.)

Why? I disagree with that spec.
For example,

asdf
    a

must be

a)
<p>asdf</p>
<pre><code>a</code></pre>

or

b)
<p>asdf
    a</p>

But the spec's answer is

b)
<p>asdf
a</p>

I cannot agree with useless indentation restriction. It must be meaningful to restrict indentation.

Conclusion

Indented Code Blocks can interrupt a paragraph

I use 4 indentation to indicate Indented Code Blocks(after parsing List item first). I mean, I think above example must be interpreted like a) case.