"Some motorists do not change the wheels at the next maintenance after 10 thousand kilometers (as required by the instructions), claiming it does nothing. Are they right?"
Both options have their advantages and disadvantages. Tires on any car wear out differently and unevenly. This is due to its design (for example, leading and controlled are loaded more), the technical condition of the suspension (silent blocks, springs, shock absorbers) and other reasons.
To tires (including "spare tire") during operation they wore out simultaneously and evenly, manufacturers recommend changing the wheels in places at each MOT, that is, after 10-15 thousand kilometers. However, each tire, getting to a new place, is first run in, and this does not always go without consequences. Let's say that her outdoor paths are better preserved. Standing in place of the one where the same tracks are more worn out, she will quickly wipe her own, since they will first be loaded more than the worn inner ones. Similar running in of tires "eats" the greater part of the resource (mileage), the worse the technical condition of the car, especially the suspension.
In addition, after repairing the chassis or adjusting the wheel alignment, the wear pattern of the tire remaining in the old place will show if anything has changed here.
Considering all this, experienced motorists change tires in places after 25-30 thousand kilometers, that is, once or twice before failure. In this case, replace (and buy) you can not immediately the whole set of tires, which suits many. As for the total mileage of the kit, in the second variant its value is usually greater.