Each to their own again... I prefer proper case as personally I find it more readable. Keywords are highlighted differently anyway (working on the assumption that their aren't many cases where a developer would be working without syntax highlighting).

Interestingly UK (and many other countries) road signs are always in proper case e.g. London instead of LONDON as proper case is quicker to read

Code readability, much like object naming conventions usually comes down to systems. As long as there is a system in place, e.g. always trailing commas, always upper case for keywords and always using the same aliases for the same main group of tables (every system has a core of at most 10 tables which are used in 90% of the queries) then it doesn't matter what the system is as long as it makes sense and is stuck to within a team