|Little cog abuse is a terrible thing to behold.|
Now it isn't always that way. I can point to many a mid-90's to late 90's hybrid bike where Shimano offered crank sets with ridiculously small chain rings which forced most users to run the big ring all the time and the smallest cogs on the cassettes all day. This caused all sorts of excessive wear issues, since smaller cogs wear out faster than bigger ones do. In fact, another byproduct of all of that was the fact that those cranks typically had riveted chain rings and you had to replace entire cranksets when the customers wore out the big rings.
Now we have 10 or 11 speed cassettes and instead of closer ratios we get these big jumps in spaces where many folks would like tighter jumps in between gears. No where is this a bigger issue than it is with SRAM's 1X (single front chain ring) set ups which are big in mountain biking and about to set sail in the road world. SRAM made a choice to run a 10T cog, in an effort to help their single 11 speed cassette attempt to cover the typical range of a triple crank and "normal" cassette. By the way, it doesn't cover that range at all, but the point here is that since you cannot put a 10T cog on a normal cassette body, SRAM has made the XD Driver, a special cassette freehub unit, to accommodate that tiny, easily worn out, and probably hardly used cassette cog. Okay, I'm calling BS here. This is a stupid choice and I feel SRAM could have stuck with the status quo in terms of cassettes and free hub bodies and we wouldn't need XD Drivers or super expensive drive train bits. But, ya know, that doesn't make sense in the marketing department.
Gearing is an almost religious debate for cyclists, but my point is that we don't need smaller cogs that wear out faster. (Thanks for putting that out there first Suntour MicroDrive!) Especially cogs that require an entirely different system to make up for the goofy idea that 1X systems are inherently "better" than having 2X or even 3X crank sets. This idea that we have to have 10T, or even 11T and 12T cogs is not for the masses. It's unnecessary, and in the end, it will result in either waste, or prematurely worn out parts, and jumps in gearing that could be made a lot closer if we started at 13.
That's my take on it at any rate.