@garethamiga
It's a complicated question.
The games you mention were commercial releases (i.e published in their own packaging through various outlets)
However, Amiga publishing is a very small business these days, so it's hard to keep down production costs by mass production. What happens is that publishers are forced to stick to small production runs and they have to look to cut costs where they can.
Here's something to consider: what is a "professional" package? Is a game that only requires a leaflet for a manual unprofessionally packaged because it sells in a jewel case? Is a program burned onto a CDR with an inkjet printed label and no manual professionally packaged just because it's in a big custom made cardboard box? I've seen examples of both.
It's catch 22. If the packaging is not professional the product won't get onto the shelves of the major retailers, but if those retailers won't stock your product you may not get the sales to support professional packaging.
A lot of commercial Amiga software has been very poorly packaged in recent years. It's a sign of the times.