as deebee's thread says attenuation is a big problem with all malt extract brews.
As one person has had bad attenuation, all extract brews have bad attenuation? No.
You can't draw huge conclusions like that from deebee's experience.
As you know, I partial mash and put on the occasional all-extract house bitter. The ONLY times I've had higher than expected FG is when I've stuffed up the mash temps in partials or used too much crystal. My house bitters' gravities are typically:
OG 1.048 - FG 1.012
which is 74% apparent attenuation. I'm fine with that.
Sorry to put your thread off-topic SJW, just had to pull in a runaway generalisation