Earlier quoted context omitted.
When the contract is purposefully obtuse and hard to understand, that should be a valid legal defense. When it's huge, falls upon people that can't justify a lawyer, and keeps changing all the time, one shouldn't even need to claim it. It should be automatically invalid.
Contract language is obtuse and hard to understand precisely because of previous challenges over meaning. There are stock phrasings and clauses in contracts that have established (by precident) legal meanings. That's why contracts seem to be walls of boilerplate. If you just wrote them in "plain language" there would be far too much ambiguity and arguing over what was really meant or implied or agreed to.
A company acting in good faith could provide both a binding version, and a version in plain language.