That's a problem for a very specific case and even then it's not always a problem. It's more something to be aware of. It does not invalidate the utility of multiple inheritance. The mixin pattern is a primary example of how useful MI can be. It use it all the time.
> Honestly, I am just going to stop commenting or offering advice on
> programming languages at all.
Advice is fine as long as it is relevant to the task at hand. General
advice should not be used as a weapon or stocks.