You're telling me I can't retire later than 99??! I plan to work past 100 dammit!
I guess to be fair it might be because a longer retirement (50+ years) would rely on too few historical periods to give reliable data on stock market returns.
I also hate the calculators that have a fixed lower floor on "% of working income in retirement", usually 80%. So if I make $500,000 it would be impossible for me to live on $100k?