I was reading about the history of the Netherlands Antilles, and it mentioned that when Aruba became a separate constituent country of the Kingdom of the Netherlands, the Dutch planned for it to become independent no later than 1996, which was accepted only reluctantly, and then rejected completely.
Was this common during the decolonization period, for nations to steer former colonies to independence even against popular opinion? If so, why?
The Netherlands never wanted the islands to be independent, don't know where you read that from. Aruba had been fighting for equal status within the constellation of the Kingdom for 5 decades before the eventual status aparte.
Eventually Betico Croes told the Netherlands and the Antilles that if they wanted to or not, Aruba will get a separate, autonomous status as per what the people wanted. Peacefully or by force. Betico Croes was shot, imprisoned etc riot police were sent over from neighboring Curacao(government of the Antilles at the time).
Eventually when the Netherlands figured they could do nothing to stop the movement, they gave Betico an ultimatum, either you stay within the current constellation or you have to go completely independent(which was never the original plan, Aruba just wanted to be able to carve its own path and have right to self-determination, without being ruled by the Dutch and the Antilles).
When the situation was presented to the Aruban people a referendum was put forth to decide whether Betico Croes had the mandate to negotiate Aruba's independence. The people voted 95% for independence with a 70% voter turnout.
Aruba's people are proud, nationalistic and (historically) conservative, however its grown much more liberal with the younger generations. Besides that Aruba prides itself on taking care of its own house, and has never taken financial assistance from the Netherlands, eventhough in the Netherlands when people talk about the "antilles" they still throw Aruba under the same light. What they do get which is logical is for instance loans at better rates because the Netherlands stands as "guarantee".
I struggle to find sources in English for this, but if you want I can share the Papiamento/Dutch sources. Its a long and convoluted story, and what I wrote above might not follow a precise historical timeline as its been years since i've read up on this, but you get the idea of how it was back then and how the Netherlands did everything they could to stop Aruba from having right to self-determination.