We can't use ORDER BY clause in View defintion and in subquery.
As both are not the final result set.
Teradata is designed to perform in most optimized path.
If there is an option to put oder by in any of above cases, it means Teradata mean to order the intermediate result set. Which means results in SPOOL should be ordered. This will degrade the performance.
So in order to have maximum performance and best PE plan ORDER BY clause is not allowed in View definition and in Sub queries or any where which is NOT the final results.