The simple answer to this question in my humble opinion is yes. The reason you have employed the services of an Interior Designer is surely because you want something different to what you would come up with and that is what the Interior Designer should deliver. Part of your design brief will be I want to walk into the room and for it to invoke a feeling of… fill in the blank but it is typically “cosiness”, “romance”, “opulence”, “historical accuracy” etc. and that is where the Interior Designer should challenge you.
I am not talking about the Interior Designer screwing up the metaphorical envelope into a ball and then setting fire to it, unless that is your brief to them, but it should definitely be more than a nudge, that envelope should be well and truly pushed. You should be presented with something that fits you as a person, your likes and dislikes, the way you will use the room/space/entire house but it should excites you and gives you a wow factor when you walk into it; whether that is in the choice of colour on the walls, a lamp, the shape of the sofa – it should be something you never would have thought about, presented to you in a way that just fits. To me when you have done that, you have achieved the ultimate goal of making the client happy AND giving then something they never would have come up with themselves and that is where I find true pleasure, that is when you know you have done a good job and are worth the money.
So to that end, if your Interior Designer is pushing you, go with it but not to the point where you are going to hate it and potentially want to move house because of what’s been done, but have a little faith that they know what they are doing because a good Interior Designer has got to know you as a person and will know when to push and by how far.