Given the nature of this site, it happens that one wants to quote something that contains a blockquote itself, e.g., as an example sentence. For example:
A run-on sentence is something like this:
I came I saw I conquered.
As you can see, the quote inside the quote is only distinguishable from its surrounding through the faint dotted line and the small indentation. Regular quotes are much easier to distinguish due to the difference of the background colour. By contrast, on most other Stack Exchanges, quotes are also marked by a vertical bar and thus double quotes can be distinguished sufficiently easily.
A makeshift alternative that some users resort to is using code blocks, but this has several disadvantages like a monospace font and no automatic line wrapping. (See this answer for examples; it does not really work here on Meta due to the desaturisation.)
I thus propose that the site design is changed to make double quotes easily recognisable as such.