I've started viewing a low WR as a guaranteed ER failure.
The failure is just up front, not down the line.
That is, if you have a higher WR because you pull the plug early, and you end up having to go back to work for a few years to bolster the stache at some point down the line, we'd call that ER failure.
By instead working those years up front, you've guaranteed that you have to work them. Still seems like an ER failure, to me.
Compare to someone else who pulls the plug a few years earlier than you, and then gets a part time job a few different years to supplement in a crash. Both of you work the same. Why is only one a failure?
Consider the person who ERs a few years earlier, and never has to go back, because early returns drop their WR low enough. They never worked the extra years. Why should your working them not be considered ER failure?
Maybe something to challenge your thinking today. ;)
(I understand and recognize all the caveats that the up front years are likely at a higher rate, you may not be able to find a job when the economy is bad, etc. I'm providing food for thought, ignore the nit picking, please.)