My two arguments against the proposal are based on physical side effects and background noise interference.
Explanation:
To start with physical side effects, the use of speech recognition technology might make users experience physical discomfort. This is due to the fact that users who interact with the system by speaking for a long period would experience dry mouth, temporary loss of voice, vocal problems and muscle fatigue. In addition, the fact that users would always speak in an unnatural way to make the system interpret commands effectively could lead to voice strain.
Also, users need to be in a quiet environment before they can get the best out of speech recognition technology. This is because background noise can interfere with commands and create a mix-up which the system cannot interpret. In other words, when an environment is noisy, speech recognition technology would find it difficult to differentiate between users voice and background noise.