Scratch

I've noticed increasingly that user suggestions are being shot down as being "good ideas, but too confusing for young users". I feel this sort of thing does neither Scratch nor the userbase any good, and it's annoying to see the same stock response used so frequently and offhandedly.

Children are far more intelligent that you seem to be giving them credit for. I highly doubt it's beyond them to understand programming concepts like "instances", or the possibility of a sprite moving off screen.
For instance, Klik and Play, a fairly popular childrens' game creation software in the 90s could handle things like that if the user required them, but users who didn't want or understand them could just as easily ignore them.

You have a wonderful community, but it's clear many of them are starting to tire of the limitations of the software. Surely it makes sense to offer a wider scope for more ambitious users who aren't quite ready to make the jump into a more full-on programming language?

I can't really say I expect every suggestion to be implemented, it's just not feasible in the short or long run, but it seems like more attention could be paid to ideas from this forum when they could make the experience much more fulfilling for both the userbase and the people using their creations.