Well, I personally do not believe in having an opinion on these things. I think that if nature took hundreds of thousands of years to evolve an animal to live a certain specific way, I seriously doubt that man was able to change anything in terms of their needs just because he decided to keep it as a human pet for the last few years.
I inherited a single male budgie (Harley) from a friend who died recently. He used to have a mate but she passed on, too, so, when I got him, first thing I did was to start looking for other budgies because in my personal experience (I used to run a rescue and have kept parrots for 25 years), the little aviary species (budgies, plets, lovies, tiels, beebees, etc) do a million times better in a flock and the smallest flock that actually 'works' as a flock (I am talking dynamics), is three pairs. I already got one pair and I am looking for two more females and one male. The new pair (Chloe and Blue) got along famously with Harley from day one (five minutes after putting the cages side-by-side, all three of them were perching as close as they could from their respective cages). They are always together, they eat and sleep right next to each other and Harley is teaching them how to eat fresh food and, as soon as I can, I will buy them a nice flight cage and get the others so they can be a little flock (budgies are extremely flock oriented - so much so that bachelors usually help parents feed their babies).