I have noticed that more manufactures are offering cabs on more models. Some models are cab only. Models as as as small as 20 something HP are available with cabs. The market drives products. The manufactures are not "shoving cabs at buyers," the customers are asking for them.
I think it has to do with advancements in technology and our standards. Historically tractors were built as minimal as possible. Automobiles were the same. Open station, no AC, heat, radio, protection from the sun and rain. Naturally, we use automobiles more frequently than tractors. Technology has improved, manufacturing processes have improved, quality of materials have improved, and overall manufacturing cost/per piece/per hour has improved. As improvements are made, we want more.
I'm 34. I have grown up on open tractors in the south most of my natural life. Hot, humid, dry, dusty in spring/summer (over 100 deg). Cold, wet, humid, windy in the fall/winter (below 20 deg). Not to mention tree limbs, briars, yellow jackets, wasps, snakes (they can fall from trees), skin cancer, and dust buggers.
I homestead 50 acres, work a full time job, and manage our rental properties. Time is very limited. My 1962 Farmall 504 and 1968 Allis Chalmers 180 were end of life for the most part. So this year I had an opportunity to buy a new tractor out of necessity. I chose a full climate controlled cab with 12 lights. Now if it is hot/cold, wet/dry, day/night I can use our tractor when time allows. Not to mention the noise reduction. Hearing is a sense that cannot be regained when its lost.
Examples:
Yesterday I had some rock dropped on my driveway. It was dark and cool when I got home. I hooked up the blade, turned on the heat and lights, then commenced spread rock till 8pm.
Earlier the summer the only time I had to bush hog was in the late evening, even then it was 90 degrees. Turned on the AC and the lights, would mow till 10pm.
Not turning back! I may get a 30-40hp utility tractor in the future. It may have a cab as well!
CT