The way I look at it, a set of similar knives is indicative of a designer's touch. For instance, many Kershaw/ZT knives are Ken Onion designs. That's why knives like the 0200 and 0300 or the Leek/Scallion/etc look similar: same designer. Becker is another example, where each is primarily one of Ethan's creations. But I find that even though they look similar, each is different enough that I'd like to add it to my stable. I actually prefer having a set of similar looking knives - perhaps all designed by the same person - rather than a hodge podge mix. Call it brand loyalty if you want, but that's why I have multiple Beckers rather than one Becker, one ESEE, one TOPS, etc.
Creativity wise, well, that's a truly subjective matter I believe. Design cues that are shared are a bonus in my opinion, such as Becker handles. However, each knife is different enough that I'd never mistake it for another; they are relatively unique, yet share genetics. For bigger brands, such as Kershaw or Spyderco, with multiple designers, the creativity is much more apparent. Yes, all Spydercos have the round hole, but that doesn't mean squat when it comes to creativeness, at least in my view. Compare a Gayle Bradley to a PM2 to a Chokwe. All Spyderco knives, but very different. The ZT0200/030X vs ZT056X vs ZT0400 is another comparison.
I guess I just fail to see how sweeping generalizations can be made that so many companies make knives that all look the same if you do anything more than glance at the knives. Yes, some companies do have parts that are very similar/the same for many of their knives, but they manage to maintain a strain of uniqueness for each so that each is useful in a different way and not redundant.