No, it was mostly racism. Singapore is mostly Chinese, as I'm sure you're well aware, whereas Malaysia is (obviously) mostly Malays and has several inbuilt benefits to give them advantages in life. A lot of Malaysian Malays were not happy about Singapore having equal racial rights, because they believed that Malays should have special benefits. This and general racial tensions led to hundreds of deaths in racial riots. The decision to separate was heavily influenced by the desire to avoid more racial violence.

I hated this Reddit trend of learning one (1) fact about a country and then linking it to literally every post or comment mentioning the country in any capacity. I really hope it doesn't carry on to Lemmy. Countries are a lot more nuanced than that.