I am still not sure I understand what is a problem about cabeceo.
Situation #1:
"I am seated in a single's section at a traditional milonga in Buenos Aires. All invitations happen by way of cabeceo. I am not comfortable with this social custom. I have to get used to it, or I will dance very little, if any, at this milonga". That might be a problem.
Situation #2:
"I am a member of a North American (European) tango community. Most people in the group are fine with verbal invitations, and I am one of them. Some, however, do not like to ask/be asked verbally. They prefer cabeceo. Perhaps, it means they are out of reach for me as dance partners, unless I get used to it."
Is that a problem? and why?