Nutty Nigel,
I don't think 450 applicants for 120 jobs is an overwhelming success story somehow ! Taken, it is for type rated pilots only and there are a finite number of those out there but a ratio of less than 4-1 is hardly a deluge of applications.
A lot of those applying will not necessarily accept employment with BA given the 15 year command wait and the pension degradation.
Regarding sims, BA is entitled to use whatever means it choses to assess candidates and if you are really desperate to get in you won't mind stumping up £250 for some practice. I guess it all depends how much you want it.
I agree with the posts that suggest it suits young guys in their twenties who, either have low seniority with their current employer or are working for an airline in a precarious position.
Regards Orion Man