to be fair the crossfire of polaris looks really compelling, for 398$, that is 30$ behind the cheapest 1070 msrp, with perfomance equal or better than 1080, total tdp of a 290X, meaning most ppl wont even have to invest on a new power supply, i think it appealing enough for ppl to ignore multi-gpu issues.
the real killer deal would be step up on multi-gpu support on engine side and driver side, i would rather see AMD droping 3/4way altogether like nvidia(i know they didnt drop them but they are more focused on 2way), to just focus on 2way support, they really have the ability to do really really well with polaris, add to that zen, if they have as rumoured a new inter-connect to allow zen to speak to gpu with lesser latency, honestly i see a good 2017 for AMD, only them can make it home or screw it up.