If it's a bank, it's because the 40 year old database they first used to first digitize their 150-year-old accounts had a maximum character limit (which is why

If it's a bank, it's because the 40 year old database they first used to first digitize their 150-year-old accounts had a maximum character limit (which is why you sometimes see 8 character maximum passwords). Old accounts that generate money just by sitting around are also the reason they never need to upgrade anything and can make changes at a snail's pace.