I'd like to ask this question in a community wiki format, because:
- Material design is a major current UX philosophy/framework.
- It is not that easy to find articles/blogs containing the drawbacks.
- There are some specific (objective, not subjective) issues with material design including its inefficient use of space and color, its performance issues with heavy reliance on animations, lack of polyfills, etc.
That said, this is a question that has multi-point answers so I thought I'd check in.
I'm generally a fan of broader questions on StackExchange, so this is one example of a topic that could be very helpful to many UX designers. Do you guys object?