A good amplifier stage is one which has high input resistance and low output resistance. A transistor in $C B$ configuration has a very low input resistance $(\simeq 20 \Omega)$ and a very high output resistance ( $\simeq 1 \mathrm{M} \Omega$ ). It is just the reverse of what is required. The $C E$ configuration is better, its input resistance is about $1 \mathrm{k} \Omega$ and output resistance about $10 \mathrm{k} \Omega$. Although input resistance of $C E$ is not very high but it still prefers better amplifier.