Do you have any suggestions for policy changes that might be effective?

This assumes that I think there's a problem with this activity, and that's an assumption without facts in evidence. In fact, just the opposite – I think that DLive making the choice to pursue what they think is going to improve the situation for them is both healthy and necessary for the growth of the steem blockchain, if that's something you care about.

They have a very data-intensive backend that is integral to the service they provide, and there are other services which would be equally data-focused, and we need multiple examples in order to determine if the steem blockchain is even a reasonable architecture for such a thing to pay for itself.

Bandwidth is not free. Hardware is not free. Time is not free.

The more competitors in a space, the better the we can determine whether or not that space is actually exploitable.

It may simply be true that DTube and DLive didn't have enough baseline differentiation to make a go of it in the environment provided by the steem blockchain. As an ecology, there simply may not be enough material that people want to engage with to keep multiple services afloat. It may be so that there aren't sufficient resources in play to keep even one service afloat, and now that DTube has another competitor that is seeing a tiny bit a traction (Vimm.TV), we may discover that another service finds it necessary to either shut down or migrate to another social media-esque blockchain as its notification backend. Which one it is remains to be seen.

But taking a broader view, all investment by a company in another company which is producing a derivative product carries with it an element of risk: the risk that said product will not be able to be sufficiently profitable to continue the project as it was. Steemit Inc., for all of its other failings, at least recognizes that and I would be somewhat surprised if they went on record in a significant way denigrating DLive for making a business decision that was profitable for Steemit Inc. for a solid year. That would be terrible business and it would create doubt in the minds of potential future application developers as to whether they want to invest their time and effort in a blockchain whose management organization would burn bridges after them.

Keep in mind, we are simply talking about delegation of SP, not any investment rounds, real money, any of that. Those sorts of things generally get tagged with contractual obligations in violating a contractual obligation is a legal matter. But we have systems for taking care of that.

As I understand it, the delegation of SP to DLive didn't come with any strings, at least any that anyone knows about outside of either organization. Likewise, neither did the removal of the delegation – because delegation is not investment in a reasonable sense. Delegation is just providing the ability for the person so delegated to work the levers of voting on the blockchain just like anybody else, only with bigger levers scaled to their SP. Effectively, Steemit Inc. didn't give any money to DLive by delegating SP, they just gave DLive the power to direct more money – and if you look at their reports on a weekly basis, which they produced and were very forthcoming with, the vast bulk of it was sunk right back into voting for creators using their digital application on the steem blockchain. In fact, by necessity, all of it was used to that end (except for a few self-votes).

From the perspective of Steemit Inc., they probably would've preferred a more successful platform that would drive more traffic to the steem blockchain. Them's the breaks.

From the perspective of DLive, they had no obligation to anyone or anything. And if the developers had a personal relationship with the developers of the LINO blockchain such that they were/are willing to take their application to an unproven, not-currently-working backend, that's their business. Literally their business, such that they have the right and freedom to make that decision.

If what you care about is a proven application being associated with the steem blockchain, that all of this outrage directed at the DLive developers by the steem community is actively working against that end. After all, it may be that LINO turns out to be complete crap and in no way provides enough working capital in the long run to keep the business running. At that point they may want to consider coming back to the steem blockchain, especially if it's done well in the meantime.

If it was me, there would be no way in Hell that I would want to put my work and sweat back in front of a bunch of ungrateful bastards like that. No way in Hell. The steem blockchain would have to be burying XRP and Bitcoin and Ethereum would've had to burn to the ground for me to come back to the steem blockchain if I were getting the treatment the DLive guys are.

You want to make sure there's a lot fewer digital apps in your ecosystem? Because that's how you make sure there's a lot fewer digital apps in your ecosystem.

Which brings us all the way back to your original question, which is "do you have any suggestions for policy changes that might be effective?"

Assuming that the implied in the state goal is the improvement and expansion of the steem blockchain, I'd say "write off your loss with a laugh and make a better bet next time," because that's the only reasonable policy change that furthers the intent.