ASCII/UTF-8 may be the most used encoding for programming languages, but that doesn't mean every programming language should use it.. Those 'gibberish' characters in Charcoal/Jelly/05AB1E/etc. with their custom SBCS (Single Byte Character Set) encodings are actually created to make it more readable than raw bytes.. Yes, it may not be as straight-forward to see what's going on if you're unfamiliar with the language than let's say a Java program where everything is quite verbose, but I can personally read 05AB1E which I learned in the past two years more than let's say Perl or GolfScript, which I'm both completely unfamiliar with.
Also, to give some counter examples of why it's a weird thing to ask for ASCII only encodings:
- In our native tongue, should we ban the regular Latin alphabet and ten digits, and start using the Chinese alphabet and numeric system?.. It's the most used character set in the world since roughly 1/3th of the world's population is Chinese (assuming most of them can read/write). 我該用中文寫剩下的信息嗎？ Your question is pretty similar by asking for ASCII only, just because you can read the characters.
- Malbolge is ASCII only. Does that make its extremely complex encrypting/decrypting nature make it any more readable/understandable? Can you see what's going on in this Malbolge answer just because it's written in ASCII? To me this entire language is more gibberish than anything anyone would be able to produce in 05AB1E/Jelly/Charcoal/etc...
Personally I never really understood why people had problems with golfing languages, tbh. I personally started code-golfing mid-2016 and primarily answered in Java 7, which I was using at work and was familiar with. I knew Java 8 was shorter with its lambdas, and I also saw all these unfamiliar languages (including ASCII-focused ones like Perl, GolfScript, Japt, etc.) which were much shorter, but I didn't care. (Almost every answer was gibberish to me at the time tbh.) I had fun completing challenges in Java 7, and that was the most important. :)
The only problem I have with codegolf languages, or to be more precise: the code-golf win-condition and what people tend to upvote in general on CGCC: a very straight-forward but short codegolf answer would get a lot more upvotes than let's say a Java answer with some very clever tricks or which took a lot of effort. BUT, this doesn't apply to just code-golfing languages, it applies to all languages in general! Still, people will also see the effort of those more complex answers and upvote for it -eventually- (but usually not nearly as much as the easier but shorter answers).
To give some examples of answers of mine (in both 05AB1E and Java):
- Short but upvoted a lot:
- This 3-byte 05AB1E (legacy) program is currently my third most upvoted answer. Unlike the title of the challenge itself (It took me a lot of time to make this, pls like.), it's a very straight-forward implementation and took barely any thought to create and post.
- Similar, this 8-bytes Java answer is not only one of my shortest and most upvoted, but also the easiest of all Java answers I posted.
- Longer and very complex answers:
- 123 bytes 05AB1E answer. 05AB1E doesn't have any date builtins, so I was calculating the next day as well as the day of the week manually. It took quite a bit of fiddling around to get it to work, write the explanation, and golf it down some more, but it doesn't have nearly as much upvotes as the earlier 3-bytes answer.
- 1290 bytes Java answer (which is even long for Java standards ;p). This challenge was unanswered for almost two years (for good reason), and it took quite a few hours before I had implemented all edge cases and fixed all bugs.
Still, whether it's Java or 05AB1E, and ASCII or a custom encoding, golfing in both languages is a pretty similar experience for me: complete a certain challenge by using the language's strong points and overcome certain weaknesses as short as possible, and have fun with it! And although I appreciate the votes of course; whether I get 1 or 10 upvotes I don't really care about, as long as I had fun doing the challenge.
I also don't really understand why you have a problem with Charcoal, Jelly, 05AB1E, etc., but not with Japt, GolfScript, etc.. Apart from copy-pasting characters depending on your keyboard, completing challenges in all of them would be fairly similar, as I mentioned in the last bold phrase above.