Some folks may complain that digital trunking systems exclude them from talking. That decision is up to the repeater owners, and DPCN runs an open system.
The limiting factor is whether they have compatible gear.
To be perfectly clear, CFR § 97.205(e) states:
Limiting the use of a repeater to only certain user stations is permissible.
This rule explicitly allows for closed repeater systems.
Are repeaters that run tone squelch closed? How about digital squelch? At some point the technology moves on and it is up to the individual operator to decide whether he wants to keep in the game. Ham radio is full of vintage gear and folks who know how to keep it going. Those folks are like the hipsters of ham radio.
Others want to benefit from technological advancements. This means they have to buy the gear themselves. 🤑
DPCN believes that the cost of entry is high enough that membership dues and fees are not necessary to be able to access the repeater sytem.