Ever since SM registered the "K" album, there have been complaints after complaints from other SM fandoms over SHINee solos being a full album. For reference, other solos from the groups release minis except for Taeyeon.
What do people really think? that SM hands them a ready-made album on a gold platter? For the full album, you need collabs, a variety of composers, and choreographers. SHINee members do the leg work for the full album themselves, same with Taeyeon. They dont sit back and wait for SM to do things for them. They actively take part in putting the full albums together.
Rather than asking why do SHINee and taeyeon solos get full albums, why do people not ask their fav about releasing a full album?
There are many reasons why idols might not like full album. Lower profit margins with alot more work is a very plausible reason.
With elfs they always brag about being separated from SM, yet they blame SM for whatever they dont like.
For reveluvs and exols, I highly suggest them to ask their favs the question instead of jumping on others.