Summarizing reasons for not introducing this restriction:

• allows more flexibility in naming metrics, e.g.
  • allows dropping .count suffixes for more concise metric names, e.g. system.processes instead of system.processes.count

Summarizing reasons for introducing this restriction:

• makes metrics documentation simpler for both author and reader
• consistency with same restriction on attribute namespaces
  • (the reason for attribute name restrictions was to leave open the possibility for attribute names to be represented as nested maps, simlar to ECS)
• allows converting bidirectionally between our dot-notation and common structured data formats such as json or yaml

I will update these summaries based on any comments made below.