Hi @jarvie! First, I really like what you guys are doing and I'm not saying at all, that closed-source projects don't have a place in our ecosystem, I just mean that the SPS might not be the right way to fund them. I agree with what you're saying in general, and most of the projects that bring value to Steem currently are closed-source. However they only bring value as long as they're here, so I think they d rather target investors rather than Steem stakeholders as a whole, in order to get funding.
Steem also has a history of closed source projects milking as much as they can and leaving the platform, and if the whole stakeholders have to pay for this, I think that we need to be sure that the code is here to stay, and not base this on personal trust. Also in the case of SteemWorld, it showed that without code to review nor periodic update posts, it was really hard to estimate what was getting done.
Some of the big voters are also looking at whether a code is opensource or not before voting, that's why i wanted to open this discussion.
About the so-called barriers, I don't think that's a thing, in the end everybody's free to vote according to their own standards.
After the roundtable we had in SF, I think it would be quite possible to fund the development of some opensource code through SPS, that could be used by the different dApps, regardless of their opensourceness.