Reasoning for why ITN continuation is horrific for Cardano's future
I think that at this point ITN repurposing is unnecessarily divisive at a time when we should be uniting for the Shelley mainnet launch. It would create a lot of ill will for those of us who could not get in on the ITN (for those of us who just missed the cut-off point, not being able to stake for so many months was bad enough already).
In addition to this, the reason for having it continue to be incentivized contradicts the hope that it can be used to test out wild ideas for the benefit of main net ADA. If real money needs to be at stake for pools to behave in a meaningful manner (for science), then if you try to put something risky and untested on there naturally the pools will deny it and we'd just be looking at a true hard fork like Ethereum classic.
Overall it's a nice gesture by Charles and the team, but I truly feel that at this point Cardano does not need a potential loose end, and that the opportunity for a testing ground in this sense is both not worth the cost, and probably will not yield the results that would benefit the Cardano ecosystem.