You cannot make the assumption that vacuum collectors as a whole prefer bagged cleaners. Nor can you say that all or most vacuum collectors believe bags are best. That's simply not true. I have over 600 vacuums in my collection, mostly bagged, mostly vintage, but I don't believe bags are best.
I've spent the past two months preparing Stan Kann's vacuum collection for display at the Vacuum Cleaner Museum. Cleaning out those stinking cloth bags was a nightmare. So much easier to empty a Dyson.
I wound up using the world's first, and best bagless vacuum - the Rainbow - to clean the cloth vacuum bags. No dust, no smell, and emptying it got no dust on me. I put the Rainbow back as clean as I put away my dishes.
I so dislike vacuum bags (cloth or paper) that I have a Vacuflo central vac at home - no bags and no loss of suction. Since it's a commercial model, it holds 30 gallons of dirt - emptying it once a year is a simple and easy process.
Half the vacuums in my home vacuum collection (in rotation - a vacuum 'of the week') are bagless machines. One of my favorite is my Eureka Ultra Whirlwind from 2002. Of course, the Dyson DC17 Absolute, made only for the USA, is another outstanding performer.
Standing in corner is that stinking Kirby. Because I use it only once every six months or so, it ALWAYS stinks like dog hair. I throw away the Electrolux bag after each use - same thing - bags stink. I gave away my Miele Gemini because I couldn't stand to throw $5 in the trash (the Miele bag) after each use. The Miele always stunk worse than the Kirby.
For the entire history of vacuum cleaners, the filtration system has been the one thing (problem) that was never solved as a final design. Electric portable vacuums were only about 10 years old when Mr. Reploggle invented the HEPA filtration 14 layer cellulose bag for the wonderful Air-Way. 15 years later, Rexair did away with the bag entirely. Filter Queen even got on the bandwagon with two-ply cellulose filter cones. Single ply cellulose bags were invented in 40's for 'regular' vacuums. 4 ply Lux bags were invented in the 50's. That was about it until Dyson made cyclonic filtration popular.