Shehroz Khan's answer to What are the cons and disadvantages of using deep learning? - Quora

Too much hard work needed to make a model work, if at all it works:-) To much effort is required to change those trivial network settings and configurations. Knowledge of'black-art' to tune/initialize parameters. Lot of computational time and memory is needed, forget to run deep learning programs on a laptop or PC, if your data is large. Lot of book-keeping is needed to analyze the outcomes from multiple deep learning models you are training on. Filters produced by the deep network can be hard to interpret.