Some users want to avoid that Flink's serializers use Kryo, as it can easily become a hotspot in serialization.
For those users, it would help if there is a flag to "deactive generic types". Those users could then see where types are used that default to Kryo and change these types (make them PoJos, Value types, or write custom serializers).
There are two ways to approach that:
1. (Simple) Make GenericTypeInfo threw an exception whenever it would create a Kryo Serializer (when the respective flag is set in the ExecutionConfig)
2. Have a static flag on the TypeExtractor to throw an exception whenever it would create a GenericTypeInfo. This approach has the downside of introducing some static configuration to the TypeExtractor, but may be more helpful because it throws exceptions in the programs at points where the types are used (not where the serializers are created, which may be much later).