From what my Mom would tell me regarding her co-workers, the majority of CMs do not regularly use their admission benefits. The ones that do are predominantly people who came through the college program, or people who were Disney fans before they started working at Disney. Some of these people would be able to justify the purchase of an AP, especially if their spouse had a good salary, but most probably wouldn't. For those that don't know, for regular WDW CMs your benefit for signing in other people is only good for 16 days a year. It's if you have a certain job or 15 years of service you are upgraded to the Silver pass which is unlimited, subject to blockout dates. When my Mom was blue not silver, they paid for my Dad to have an AP, but that was a unicorn among her co-workers.
Of the CMs who don't regularly use them, a large chunk of them never go at all (see the CFTOD mentioning 50%, never using them) and a smaller chunk who go when the grandkids, nieces and nephews, etc. are visiting, and they are very excited that they are able to do this for them. There is also a group in which the employee has kids and does use them, but I would guess this is a smaller group than existed in the 70s, 80s, 90s. Disney has replaced these types of people with people earlier in their careers (no kids), older people who are doing Disney as a second career (kids have grown up), International workers (whose kids may be on an island or different continent) or outsourced that job. In the higher salary jobs, maybe some would pay on their own, but I would guess the majority would not buy admissions. Maybe for somebody's birthday.
You know that Defunctland video about Fastpass+ usage. I'd guess it would mirror Main Entrance Pass usage fairly well too. A small group that is hitting that pass for all it's worth, a middle group that uses what Disney expects (maybe a few days in a row when family visits, and a few single days for things like Epcot event or new ride, for a total like 5-7 days), but the largest group doesn't use it at all. The largest group willing to purchase for fun, are in the smallest group overall, so wouldn't tip the scale.
So that's a long way of saying: No. Most CMs would not pay for fun.
But if you want to see some impressive math... I used APs to make the math smaller. Another way you could look at is, using the blue pass 16 separate 1-day park hoppers. A spouse could bring in 3 guests, and the employee could self-admit for a total of 5 people. 5 people x 16 x $184-$247 = $14,720-$19,720. Lesson: If you are ever fortunate to have access to a Main Entrance Pass, USE IT!
