Why is most (all?) mikrotik hardware using passive PoE instead of active? I tried to search the forum and the last discussion I found of the topic is four years old and basically amounts to price and not having adapted the standard yet. Are there any good arguments for why this is still the situation?
Are you sure? Have you checked the specs? There is a vast mixture of passive / 802.3af/at options. Crazy one but it couldn't be said that "all" are passive only.
It's cheaper. therefore, SFP is used, not 2.5G ports, and passive poe.
Ok, I’ll admit I was looking at the lower-range routers and switches so maybe it is just an affordable option?
Once said that - generally speaking - 802.3af/at/bt is a mess with devices from each manufacturer not really-really compatible with devices of other manufacturers or - if you prefer - not fully-fully compliant with the standard (and Mikrotik devices have their own quirks), it is not like the 48-57 V are really-really needed, particularly for SOHO installs.
If you take any normal AP or similar device (i.e. what normally is PoE powered to get rid of the power brick, you will find that rarely they exceed 802.3af (around 13W) and need 802.3at (roughly 25W).
With the worst Cat5e cable you can find, for 13W at 50 m you will get 21.5 V, losing roughly 10% power, but in a more realistic case of SOHO, at 25 m you will get almost 23V losing only 5%.
So, passive (and 24V) is adequate for most "normal" cases, the circuitry is simplified and there are less things that may go wrong.
In a more "professional" install, where distances are greater and to have better compatibility with other manufacturer devices (when there is actually compatibility) then 802.3af/at is preferrable.
The reality is that if we consider the cable products that China supplies, then in the budget segment, the discrepancy between materials and markings is the least of the problems, most often everything that is cheap is of terrible quality and the voltage drop there is quite high.,
If we consider inexpensive mikrotiks, these are hex RB750Gr3, AX2, L009, everywhere the quality of materials is disgusting, AX2 has a very bad plastic, and many small components, like the SD card(rb750Gr3) tray, microswitches for buttons, are all disgustingly cheap. we just recently had a topic where it was mentioned that metal flash drives should be used for the AX3, otherwise they create interference.
all this is done with only one goal - to reduce the cost.
But it's not that bad! I really liked the AX Light series(AX Lite, LTE6), they are really very nice and high-quality devices.
What I worry is that I end up frying some equipment that’s not poe enabled if I mess up the cables. I am in the market for an Ethernet switch and need to hook a pair of existing AP’s and a NAS to it. Small potatoes really, and I am something of a noob so I want to be sure I don’t mess up.
Yep, but there is some "safety" also in passive PoE.
The powering device checks the resistance on the cable and doesn't provide voltage is it is below 3 KOhm (26.5 KOhm for high voltage PoE).
But you are right, better be safe than sorry.
The "safe" solution is to position a splitter near the non-PoE enabled device, this way, no matter if the cable has (or has not) PoE on it, the device won't get any.
For Gb connection, a Mikrotik RBGPOE:
https://mikrotik.com/product/RBGPOE
that can be used BOTH as injector and splitter :
(though to actually use it as a proper splitter you would need an additional DC jack gender-changer) would do nicely.