Why are Oracle table/column/index names limited to 30 characters?

Question

I can understand that many years ago there would be this kind of limitation, but nowadays surely this limit could easily be increased. We have naming conventions for objects

Answer 1

Given the practical necessity of identifier length limits, good design restricts the length of actual names to avoid hitting the ceiling when the names are combined with each other and with prefixes and suffixes.

For example, a convention of naming foreign key constraints

FK__ 

limits table names to 13 characters or less; most databases are going to need more prefixes and suffixes, further limiting the length of table names.