Ask HN: finishing projects that got stale?

So as a starting developer working on a project I'll typically run into the following cycle:

1. Come up with a project to work on that I think is super-cool and that I can execute.

2. Start working on project for weeks/months, do pretty well, make it past the halfway point and get most functionality going.

3. Uh oh, this thing I've designed looks and feels like crap, even though it pretty much works. Motivation starts dipping. Innovation and creativity fade.

4. Either gruelingly force myself to finish something I once thought was so cool (but I now feel is a burden), or abandon it and go back to step #1.

So now I have a list of kinda-interesting but unfinished projects that I can't really stand to look at. Why does this cycle happen? It can't be solely because of my lack of good UI/visual design.

And better yet, how do I motivate myself to finish these projects that I've abandoned? They're still worth completing for the sake of building up my portfolio, but the motivation just isn't there.

Looking forward to hearing your insights.