Please bear in mind that Snap! development is done almost entirely on a volunteer basis. Bernat is the only one paid full-time (by SAP) to work on Snap! development, and his primary specialization is the community site rather than Snap! itself. Jens and Jadga are also paid full-time by SAP, but SAP wants them to spend most of their time creating MOOCs and giving talks. Michael, Joan, and I are not paid to work on Snap! at all.
And we have a huge backlog of really important work.
So "wouldn't it be cool if..." just isn't a good reason for us to spend time implementing anything, unless it'd be really, really cool (such as first class continuations) or really, really trivial to implement (of which there aren't any good examples, because everything turns out to affect everything else, when you take into account things like translations, hyperblocks, and so on).
Sorry; we'd all love to be more relaxed about the whole development process.