It is DEFINITELY not a bad idea!
The problem isn’t with the idea … the problem is that SmartThings shows very little interest in developer feedback to improve their architecture. For example, the entire “Capability” paradigm is very good, but has gaping holes and inconsistencies. I raised that specific area of concern 1.5 years ago, and it died on the vine About the Capability Type Suggestions category - #8 by tgauchat
Inter-SmartApp communication is an integral part of the SmartThings architecture and is meant to be done via Devices.
Are there legitimate needs to expand this functionality? Sure … but … take a number?