For me, as a generation 2 (I think!), there are probably two issues:
1. Knowing where to start and how to progress. There is some quite good documentation, but it all feels a bit disparate at the moment. IndieWebify.me is a good start, but I feel like there could be a much clearer, more cohesive process that lets you jump in at the level you're at and not end up following too many links in too many directions. I think John's on the right track with "shorter how-tos that don’t link off too much... and [that] have a smaller scope". Possibly even a single, downloadable PDF that's well structured, written in less technical language, and with simple diagrams to help adopters understand the architecture.
2. It all still feels like quite a lot of manual tinkering is required, and I don't want to go down that rabbit hole too much and get distracted from the reason why I created an indie site in the first place: to blog! Having said that, I realise IndieWeb's got to go through this stage to get to a more user-friendly state of things. The plugins certainly go a long way to encouraging people (me included) to adopt the features. I'll be experimenting with those.
Thanks for all the work your're doing, everyone. I can see some of you have invested a lot in this, and hopefully that will pay off in the years to come. Like I say, my focus is on blogging (when I'm not working or focusing on my wife and kids), so I don't have a lot of extra time and energy to spare, but where I can contribute to IndieWeb I will.