I must have said it hundreds of times on this board don't start your bike every few weeks when not used even over winter. Sediment does and will get through filters, it this that causes what you call gum.
Strip almost any carb and you'll find what looks like brown staining in the corners of the float bowl, look at it under x20 magnification it's tiny particles i.e. sediment. Vacuum taps stop more fuel entering the float bowls once the engine is turned off, the fuel will evaporate in a few weeks in winter possible days in summer depending how the bike is kept. Constant refilling and evaporation will encourage more sediment, eventually it will block the pilot jet/s. The vast majority of bikes I get in with blocked pilot jets over winter, the owner has run the bike every week or so. They stop starting their bikes every week or so and surprise, surprise they don't get blocked jets anymore. Now I'm not saying you'll never get it but highly unlikely.
What causes it, in my experience it's not just the fuel, it's a few other factors, bad fuel storage/transportation forecourt fuel tanks contain water which sinks to the bottom, it's not all bad as fuel floats on it and any crap in the fuel sinks to the bottom. The tanks and pumps need servicing i.e. the tanks pumped out and replaced every 20yrs, small garages and some fanciseses aren't that good with this maintenance. I know of garages who haven't replaced their in well over 30 yrs, they never shut in all that time. The crap and corrosion in the tank builds up in the bottom, if they allow them to get too low this can get sucked up and/or when they're filled it stirs it all up add that to sides corroding you get tiny particles (sediment) suspended in the fuel. If you're unlucky enough to be one of the first to fill after they've refilled it will stop the engine, this happens surprisingly quite regularly. Other sources are corroding bike tanks, dents being the biggest culprit and old top up fuel cans metal ones being the worst offenders.
Some bikes that are barn finds or just taken off the road and left for many years, can and do suffer other forms of blocked carbs, sediment, dissolved gaskets/O rings residue, water/damp/moisture. Many lacquers applied to a lot of surfaces, degrade over time and the surface becomes sticky and soft this also causes real gum.
Yes fuel will slowly be less efficient/volatile (go off) but in my experience it takes at takes years even more. My ZX10R is stored (parked) at my son's, just turned off and left, it hadn't been started for well over a year approx 18 months. This April I started it and rode it, pictures are in the photo challenge, it started first go no loss of power or drivability. My XJR nor used for 10 months, again just turn off and sitting in my garage, primed the carbs started first prod, my Fazer 600 once stood for almost 5 years, it started, yes to wasn't quite as it should have been but topped up with fresh fuel and all was good. Common denominators, I don't start them until I want to use them, I only use quality fuel Shell/Esso etc, no dents and I don't use contaminated fuel cans.
Now what will be interesting is what effect 10% ethanol (E10) will have, current E5 as far as I can tell is doing nothing.