Well, it was not in good hands from the very beginning.

I think the problem has been perfectly demonstrated.

It's with personal preferences of each particular coder.

No other problems found.

Use of square brackets as identifier's delimiters allow to use any chain of characters as objects and columns names.

Some people hate to use them - but it's not SQL Server's problem.

Actually, not using square brackets creates a bit of an additional work for the compiler.

Because lack of square brackets forces it to check every identifier it meets in a query against the list of keywords, other language constructions, while opening square bracket clearly tells it - everything until the corresponding closing bracket is an identifier and nothing else.