A disruptive innovation creates a new value network and therefore a new market. By doing so, it disrupts an existing market. Usually the market is taken by surprise.
The usual reaction from the leaders of the markets as they were structured before is for them to abandon the market and leave a large market space to the disrupter.
Usually, the disruptive product is cheaper, more convenient and simpler.
The initial customers are those unsatisfied with the current market offer, but as the disruptive product improves, it gains a wider acceptance and eventually conquers the market. Precisely because the disruptive innovation touches customers not previously serviced by incumbents, the latter tend not to react.