[ziszis]

Every new product needs to overcome the formula "product value >> adoption cost".

You can simplify and call OpenTable shitty, but they met this threshold with their customers. Their customer looked at their product and said, it's new and different, but it is worth it.

If you can't displace an existing solution you haven't got it right.

If the value is significantly greater and it is only about UI familiarity there are many ways around it. One way is to emulate the UI of the product you are displacing. This famously happened in the Word vs. WordPerfect wars.