You are playing a fool here...The net effect of this would be for masternodes to be sold en masse
And now you're the one making blind assumptions with no evidence. In fact the evidence is to the contrary.
Bitcoin has over 10,000 nodes and not one of them gets a satoshi from the block reward. You quote an ROI in Dash which you must know is meaningless because it doesn't account for the capital gain or loss on the collateral.
If the network can sustain 5000 nodes with a net negative ROI in dollars then we can easily have 5000 nodes with a net positive one even if it means a revision of the block reward back in miner's favour. There are always takers for nodes at any price as long as they're the least bit profitable, same as mining. The difference is that miners invest more into the network as price rises (they have to) while masternodes drain more from it as price rises (proportionally). Their costs are fixed.
If reward ratio was shifted back, nodes would still be profitable. Sure there may be a shakeup but there's always takers for a profitable operation. You may ditch your node because you wouldn't be happy with the new high-mining protocol but someone would come along and buy it from you that was and they would be a far leaner and more efficient operator for the network.
Under your correction it would become 0.28% all of which would be consumed in hosting fees
Even a masternode reward ratio of 20% and Dash at HALF these prices, they would still be profitable. It would represent around $104 per month and would not be consumed in hosting fees which are around $20 per month. More to the point it would allow the currently wasted reward to be redirected into mining and start to address the issue of stabilising the capital value.
The risks you cite have already been taken - we've had the 3 year selloff, way beyond LTC, XMR et al. They hit rockbottom and bounced, even in satoshi price. We hit rockbottom and are still digging because we have this enormous deadweight to support in non-performing masternode margins, paid out of the part of the supply which our competitors have made available for mining budget. That's why they beat us on store-of-value even though we may beat them on "features".