Strangely my path both supports and counters your statement. Likely in no way typical. But given the prevalence of negative comments regarding grad school in response to this article I want to say:
I thought getting my PhD was fun and a great time in my life.
(looking back with 30 years of hindsight)
Start to end my PhD was a roughly ten year period.
Round 1: (in support of "no fun") Had a great undergrad experience (thank you Harvey Mudd). Entered grad school with goal of teaching at an undergrad only liberal art college. Frequently read Chronicle of Higher Education so I knew there was an over supply of PhD to tenure track positions at the time, but I was special, so no problem. Passed qualifying exams. Received great advise and directed away from my area of interest because it was already full of tenured faculty and was told, correctly, that departments were so full up in that area and it would be near impossible to get a tenure track position in the sub area of CS. I started thesis, published, even had expanded version of a paper invited for inclusion in book. I was playing by the rules, but seeing how the sausage was made, I was ground down and quit
Intermission: (An aside, I was always amused as an undergraduate how the janitors would enter classroom and empty trash can during ongoing classes. So my first post drop out job was a version of that). I got a job as sysadmin in the department I had just dropped out of. Got to go to former professors offices to fix their networking problems, change printer paper for them. Then former classmate was starting a company and I got hired by member of my qualifying exam study group to be first hired employee and company he was co-founding. After quitting that job, I was visiting a friend back in Claremont who was busy inventing MIME. Mentioning that I was unemployed, he said HMC Academic computing was looking for new User Support and Education Coordinator, the former one having quit just before school started. Walked me over to Director of Academic Computing's office. Half hour later I had a job. (Not quite janitor, but closest to cross it off bucket list). Being back in the environment rekindled the dream that sent me to grad school in the first place. So I reapplied to grad school
Round 2: (not following the rules, but having lot of FUN). The solid advice, one shouldn't pay tuition to go to grad school. Me, I paid tuition out of my own pocket, received no institution support as RA or TA. Basically doing it all wrong. My original advisor, in immeasurable kindness, agreed to again be my thesis supervisor. While providing no financial support, I was still a time sink for her. There were moments of pure joy when I got to be a non conformist grad student (aka pain in the butt). Like when the department secretary sent out a letter to all grad students asking help moving furniture from point A to point B. Instead of being a helpful department servant, I got to fire off an angry letter (reply, faculty include, all of course) saying that I was paying my own tuition and wasn't there to provide free labor. I had fun because I was in control of my time. I had fun cause there where great recreation classes on campus. I had fun cause the local vegetarian cafe was the default punk music venue of the city. I have fun cause I was doing things on my terms, studying in a field that I love.
Postscript: Despite odds, got a tenure track position and was assistant professor for 3 year. (Reality was not the same as dream.) After that got another job, again through a (different) member of my qualifying exam study group. Approx 8 year after receiving PhD, I was more or less retired, having easily achieve the financial goal I established as a grad student learning how to enjoying life on a frugal budget.