Whether or not full text search is more scalable than a full table scan depends on the use case - if he's continually inserting and deleting rows from his table

Whether or not full text search is more scalable than a full table scan depends on the use case - if he's continually inserting and deleting rows from his table while doing relatively few queries, it may very well be more scalable to do the full table scans to avoid the continual overhead of maintaining the full-text index on inserts and deletes.