Indeed. For example when are you ever going to hear anybody talk about say an Astre? Doesn't mean it's a bad bike if you never heard of it...
If the frame is made of anything worthy of having a sticker telling you what it is made of, it can't be that bad. Excess brazing material, or a lack of it - if you can stick your fingernail under a lug - is not a good sign of quality. 27" wheels were rarely used on bottom of the barrel sport/road bikes like AMFs, etc - though common on even good three speed bikes. Etc. you just have to know what to look for on a bike to bike basis.