Trademarks last as long as you keep them registered, and protected. Bass' red triangle has been a registered trademark for a couple hundred years.

Coca Cola has been a trademark for 100. do you think people should be able to use Coca Cola on their products?

The fact that the trademark is simple, i.e 5 colored stripes in particular colors and order doesn't mean its not protectable, e.g. bass's triangle, the olympic rings, red soles on high heels.

As for the UCI being a non profit, that's irrelevent. Pretty sure the IOC is also non profit.

I'm sure having more rainbow stripes on more things will certainly increase the riding of bikes.