Although I can understand the design that went into this, it also just felt completely wrong.
That's kind of a damned if you do damned if you don't situation, which leads to picking the lesser of two (or more) evils.
Games have chosen both+ ways. Like, let's look:
So in an open-world game with multiplayer and other players present, you have an event occurring that players can participate in, and you reward the players for participating. There are basically three ways you can go, and they all have significant downsides.
1) You don't reward the player for participating at all unless they participated by actually, intentionally and successfully helping with the objective
i.e. fighting off some monsters, putting out a fire, planting some crops, whatever. The upside is, players have to choose to interact, so if it's important to your game that people have that choice, this is the way. The big downside is that eager or fast players can effectively "lock out" other players from getting any credit, especially if you put a minimum value for "successful" to count.
World of Warcraft uses this design a lot. Even when they try to use 2 (as I shall explain), they often end up effectively doing this.
2) You reward the player for participating based on how much they participated.
This can go as low as just being in the right area, but it usually requires at least trying in most designs, and the more people do, the more they get. The upside is this encourages strong engagement for the whole event (simplifying slightly) from people who want the rewards. The disadvantages are that it strongly discourages people who "come in late" from being much, unless you make it very easy to "put points on the board", and if you make it so just being in the area counts, you remove choice.
GW2 has used this design a fair bit. WoW sometimes uses this but de facto in most cases it becomes more like 1 because they tend to have narrow ranges of reward with low minimums and low maximums (c.f. the Dragonflight event where you follow the big tree around and fight stuff, it's very easy to reach the minimum to score, and pretty easy to hit the maximum at which point the only reason to contribute is to ensure the event finishes promptly!).
3) You reward players equally for "participating" no matter what they did, so long as they were at least present.
This has the upside that you can't get left out if you even get there, which can be very valuable if that's a risk (esp. if events are complex or deadly or brief), but has the downside of, as you note, not giving you a choice, which is bad for RP and immersion, and it also potentially discourages people from actively contributing, and encourages them to just stand around and perhaps passive farm an event if it's going to keep happening (there are bandaids and workarounds for the devs to deal with that, but still).
Pretty sure World Bosses and possibly Legion Events in D4 work this way, but I could be wrong.
There are other nuances of course, particularly with 2, where the base to contribute and maximum contribution value can make a huge difference to player behaviour.
