Fedors legacy was definitely hurt by his losses. The same would go for Anderson, you're as good as your last these days to most fans.
No one credible thinks that Fedor isn't the best HW ever.
The only thing that was tarnished by Fedor's losses was his aura and his talent relative to a an all time, mythical scale.
Mainly because Fedor's downfall seemed way too coincidental with consistently facing the best fighters he had fought in nearly a half decade.
Fedor's all time p4p ranking was tarnished more by his extremely protected record and the fact that he avoided the young guns that were coming up after his division started to rise from the shitpile.
Even the fact that he fought a guy like Brett Rogers instead of Alistair Overeem when he was contractually signed for Strikeforce is a huge watermark on his resume. Even the Werdum fight was incredibly criticized at that point and he lost that fight...., and this was the starting point when people besides me and a few others in the know about Fedor's shambolic record padding started to turn on Fedor and realize that something was amiss. People started using his management company as an excuse, other people just turned on him completely.
The fact that the so called best HW in the world had over 5 fights in an organization and never fought the division champion when most people wanted to see the fight for a majority of those 5 years is incredulous.