I don't think people have a hard time understanding that you shouldn't use the <blockquote>-element for something which is not a quote. But html tables had a more troubled history because for a long time html tables were the only way to achieve certain layout effects, which was not supported by pure CSS in mainstream browsers, because they didn't implement "display:table".
This article is well-intentioned but I think it also contains some language which muddies a pretty simple concept. Eg. it states CSS Table has a key differentiation over HTML Table. It can choose not to be a table by just adjusting its CSS properties. Something that HTML Table is incapable of. The sentence seem to confuse semantics with presentation, which is what got us into this mess in the first place.