that's not what's being asked for here though is it? i don't think i've seen anything encouraging alignment switching penalties, what is being presented is the minimum requirement of 'either play as the alignment your sheet claims you are or accept the alignment change'
Well, to be fair, I did discuss that my current campaign has a variety of repercussions for changing alignment. At the most mundane level, there are faction/reputation rules. Then you have devotion/concordance to give mechanical weight to devotion to a particular deity. Then there is alignment. Cosmological factions if you will.
But the repercussions mainly affect story and flavor. There is no wrecking the character. PCs may have to ally with a different guild, patron, order, etc. The cleric / paladin can switch devotion to another god. There are areas and enemy auras that can affect PCs of certain alignments, positively or negatively. But these a fairly balanced in my current campaign. The closest thing that I can think of that could be construed as "wrecking" a PC is that certain magic items may no longer be attuned to and so if a PC were attuned to magic item that requires a specific alignment or harms those of certain alignments, they may no longer be able to use a magic item they have.
But I have not had a single player complain about it. There has been discussion about how certain actions may be seen as against certain alignments, but there have been no arguments at the table about it, certainly none that go anywhere close to anyone being upset.
I am not the type of DM that imposes certain styles of play. It is not my way or the highway. Before we start a new campaign, I usually give several suggestions as to the kinds of campaigns I would be interested in running. When all of us come to a consensus, I'll distribute a campaign guide that states any variant or homebrew rules, which is followed by discussion and suggestions by the players. During the campaign we, after discussion, we have dropped certain rules or added others. Again after discussion and reaching consensus. I feel fortunate in that we've always been able to easily reach a consensus.
In my first two campaigns in 5e, starting soon after the PHB was released, so for most of my time playing 5e, alignment was basically ignored. My first campaign was more about navigating the politics of 8 eight kingdoms and that was just tracked by plot and NPC motivations. My second campaign was Curse of Strahd, and the focus was more on sanity. Keeping sane and escaping Barovia. In my current campaign, alignment is very important and has mechanical weight. And it is just as fun as the campaigns where alignment was mostly, if not entirely, ignored.
I guess that is why I take a bit of offense when my use of alignment is characterized and my wanting to impose something on my poor players. We all agreed to this and we are enjoying it. If we stop enjoying it, we would discuss and change it.