You mistake competition for doing the same generic or popular shit that everybody else does. Trek has always been an idea-, not a character-driven franchise and it certainly shouldn't become one just because it is in right now.
While Travis was played by a bad actor and hence did not get any Travis episode anymore after Fortunate Son and Horizon (vice versa with DeKelley and Picardo, once it was seen that they portray their characters well they got more spotlight) I fail to see your problem with Harry Kim. He was perhaps not the most interesting character but you can't have an entire crew full of eccentrics. If you are on a normal ship like the VOY you are bound to have normal people like Janeway, Tuvok and Kim aboard. DS9 featured so many interesting characters because they were in the middle of nowhere with many non-Starfleet characters.
If the guy playing Travis was no good, shouldn't have not hired him in the first place?
I fail to see how nothing characters like Travis and Harry Kim will make a show less generic.
The problem with Harry Kim is that he is dull, there have been normal characters who can still have character development and interesting focus episodes, Harry Kim has no character development, he is the green Ensign from start to finish. He had one good character focus episode and that involved a future version of himself.
You can remove Harry Kim from the show and it wouldn't really effect the show. There is a huge difference between normal and dull as dish water.
Ideas are important, but you need interesting characters to drive the plots. Robert Beltran was given so little to actually do as Chakotay, that he started to phone in his performances, that is not the sign of a well written TV show. You need to avoid that kind of thing for a new Star Trek show, learn from mistakes from past shows to develop something interesting for today's market, not the market of the 60s or the 80s.