If you are having a problem with mud and rubbish getting trapped inside gaiters then it's badly designed.
I used them on my BMW R75 for several years in the Oz outback with many a ride through deep mush and nothing got in. That's because they had a breather to allow air to come in and out. The breather was vented to the fork shrouds which contained clean air and a filter. Gaiters without breathers expel all their air, then suck in whatever is out there, hence the grit and rubbish.
It's a fashion thing derived from motorbikes. Racing bikes didn't use them, so the fast wannabes removed their gaiters to look cool. The manufacturers were happy to leave them off because they were able to sell more forklegs. Besides motorcyclists tend to bend them before wearing them out anyway 🙂