Are they just being pretentious, or do they have a legitimate reason?

I'm glad you found the info helpful.

Instant coffee can sometimes be looked down upon, partly due to its history.

When it first became popular, instant coffee was seen as lower quality compared to freshly brewed coffee, mainly because early versions had a more bitter, less nuanced taste.

Over time, as coffee culture evolved, the focus shifted towards artisanal and specialty coffees with complex flavors, making instant coffee seem less sophisticated by comparison.

However, it's all about what you enjoy.

There's no wrong way to enjoy your coffee.