You apparently weren't reading the same articles that I was. So much of the Star Trek that was produced through the early '90s was produced for one purpose; to appease the fans. Making certain the source of their profit margin is happy is a huge inspiration for movie studios to do many, many different things they often think are bad ideas.
Sequel this, same old same old that, copy, copy, copy isn't what the fans want, it's what the studio wants, because that's what the bean counters tell them will make money. But when the fans tell them "Give us this or we won't watch any of your other movies" that gets the bean counters to shut up, cast about for other ideas, and eventually cave and say "Give them this, or we'll go broke." It wasn't a studio decision that STV was poorly received so they want to do another one. It was fans saying "We want a better film for the last one from the original crew." And when the studio realized that the 25th anniversary was coming up fast, they put together STVI very quickly to make sure the fans wouldn't ruin them for not doing something for it.
And for the record, during the time STV was out, it was often said that it was intended to be the last one. Just as each film was intended to be the last one. Heck, TMP wasn't ever intended to have sequels. Until Paramount got tired of fans asking when one would be made.