By the by, the person in charge of the project is clearly an idiot. If you didn't need to use JS to hide/show the blocks, it would make sense to avoid JS for building them. Then the page works even for people who don't enable JS. But given that the page won't work at all with JS disabled, why not build the blocks in JS?
An optimist sees the glass as half full.
A pessimist sees the glass as half empty.
A realist drinks it no matter how much there is.