Not necessarily. It depends on the size of the room, the acoustical properties of the room and set up and it's not really a performance issue in and of itself. It is performance with your system and the room.
It also depends a little on the sound you are looking for. If you want highly revealing, full-range and lows that go down to just above sub territory or a little bit into it, then bookshelf speakers alone won't be up to the task. You could add a sub to get there though. Even with that, it is unlikely the bookshelves will be true full-range or highly revealing. They will likely be highly resolving though.
So rule of thumb is if you are after highly revealing, the best bet is full-range towers or the like. If you are after highly resolving then the doors open wider for both bookshelf speakers and floor-standers. However, it is not just that, you must take room size into account. You don't want a pair of say, floor-standing Elac Adantes in a room that is 11 x 12.
Keep in mind that what you may hear in a shop from said speaker will likely be not even close to the way they will sound in your room even if you use the same electronics in the shop. Set up is everything...or almost everything. I've heard a pair of $250 bookshelf speakers sound very good (if looking for resolving rather than revealing). however, that was in a small room, that same trick won't work as well in say a 20 x 14 room unless you listen near-field.
You might want to look for efficient speakers either way, say something in the 89db min and higher range. This will widen amp choices as well.
Just my take on it.