Thinking out loud - maybe the products ICOs promised to create will start popping out and we're on the verge of shift in thinking about alts. Now most of them are perceived like purely speculative assets or how I like to call them "weaker and clearly sick children of BTC". If they will, one by one start proving they're valid, prospective businesses, they may as a group become less dependent on BTC.
But I don't see this yet. It will come, but I don't think it's the time.