I stayed offsite as a child in the '1970's, with my family. Then DH and I stayed offsite on-the-cheap in the '80's and '90's. We were so happy just to be able to go to FL and we were sightseeing commando-style all day long. When we finally did a split stay offsite-to-onsite, with 3 kids, we were hooked to onsite. Became DVC members, the whole 9 yards! But we'd only really compared onsite to cheesy offsite motels.
Some years later, after enjoying timeshare condo vacations elsewhere too, we tried area offsite timeshare resorts. These are true resorts, not fancied-up motels - they have excellent amenities both inside the suites and throughout the resorts. We ended up selling our DVC and keeping our other (less costly) timeshares (go resales!!!). We've mostly enjoyed spending a week offsite with a couple days onsite tagged on to the end of a vacation, mostly to use the themed pools with slides when our kids were younger.
Now, with everyone grown and preferring to use cars everywhere, we still take a rare exchange into a DVC 1BR or 2BR condo (don't care for a studio or hotel room for more than a day or two) but we also love the relaxation we experience outside of WDW at other, very nice timeshare resorts. Area resorts have really stepped up over the last decade too, adding more upscale decor and amenities, better pool areas, more pool parties and resort activities.
DH prefers the offsite getaway from the heavy Disney promotional marketing throughout the property (I don't mind it as much, except for the canned "voice" on shuttle buses). I like the themed buildings and grounds onsite. But we both choose offsite when we're doing more offsite activities than Disney parks to avoid traffic in/out of WDW..... Sea World, Universal/IoA, state parks, beaches, boating, resort activities, smaller attractions. If we're planning to spend a lot of time at the Disney venues or we're bringing along one-timers (probably won't come back, due to finances), we're more likely to stay onsite for the slight convenience - still in DVC condos, not Disney motel/hotel rooms.
So while I wouldn't say we've converted completely, we definitely lean heavily toward offsite

for most trips, barring particular circumstances.
