Yeah there are some tweaks required to make a standard distribution realtime stable. Some are suggested by the renoise team, others are more extensive. Some distributions are already tweaked, i.e. there are some media/audio/video distros.
Honestly, it is up to the distributor to configure the system, not up to the renoise staff. Renoise does work when used “naively” btw. - but you have to use a very high latency (i.e. > 100-250ms) for it to work glitch-free. Maybe the manual isn’t clear enough on this?
To be able to use renoise with a very short latency (i.e. 10-20 ms, or even like 40 ms), that will allow tight interaction and realtime recording of audio/midi, you’ll have to tweak the system or use a specialised distro.
Hey and it’s Linux. People are used there is no support but communities to ask and wikis etc. Supposed to RTFM or just use Google to find your way… Linux was way more elitist in the beginning, first Suse and then Ubunutu had changed that a lot. People were used to that if you use it, you’re actually a power user able to fix things yourself. Maybe that’s why it can be a little unfriendly to newbies - the people making the docs etc. are all nerds who are used to being able to fix it themselves, telling newbies to RTFM before asking by default…
P.S.: look what I just did here, the linuxaudio.org link in there is the best guide on tuning a system to get that low latency: