There are 2 things that can clog a nozzle: lumps and hardened ink. Lumps can be either ink ingredients that did not dissolve properly in the manufacturing process or foreign contaminants.
Hardened ink is usually caused by ink that stays in the nozzles when the printer is left unused for too long. How long? Its hard to say. I usually like to print something at least once a week, or at least power cycle the printer once a week. A printer when turned on usually squirts a small amount of ink into the waste pad to clean out the stale ink. That might be enough. The ink nozzles are covered by a cap whenever the printer is properly powered off to minimize exposure to the air which causes the solvent to evaporate and the ink to harden but it still happens. <source>
The frequency of lumps and foreign contaminants is determined by the quality of the manufacturing process both for original inks and for refills. Almost all original inks are of high quality while for refill inks, the quality is more variable. Also, for refills, there is a theoretical chance of foreign contaminants like dust entering the system unless you use a refill system that is not exposed to air.
If you do get a clogged nozzle, you can use your printer's cleaning utility. If that doesnt work you can get more aggressive like emptying the cartridge of ink, flushing it with cleaning fluid and filling it with cleaning fluid and running a clean cycle on the printer. If the nozzles are replacable you can try soaking the nozzles in cleaning fluid. There are several commercial cleaning fluids available but distilled water sometimes works.
If however, cleaning doesnt work, then you have no choice. You have to replace the nozzles. If you have a fixed nozzle then you have to replace the printer. If you have replacable (also known as disposable) nozzles, then you can merely buy a new cartridge. This is the big advantage of replacable nozzles.
wiki article on nozzles
So yes, its possible that by chance, your nozzles wont clog. However ...
If it doesnt, then you're ok. But if you are not lucky, then having replacable nozzles is an insurance policy. So the bottom line is :
All nozzles will probably eventually clog so the best policy is to have replaceable nozzles.
note: that to be fair, I did not mention any printer brand. My own personal printer is one of those major brands which favors replacable ink heads.