drugs do not produce good art. they just make you think your art is good and may or may not appeal to other people on drugs.
i only use drugs to overcome my crippling anxiety/inhibitions about producing art- and stimulants usually work the best for that, as they make me more focused and actually increase (or at least don't fuck too much with) my fine motor skills.
the art still comes from my own head, though. stimulants just make them sound awesome instead of stupid (if your main problem is confidence, as mine is) using drugs to inspire you to create art is cliche and pretentious and is usually used as a substitute for real creativity- not that i'm saying you don't have any, but to me something individual is better than the same type of drugged up art everyone creates on psychedelics because you're not really able to do much.
i don't look down upon using psychedelics to inspire ideas and then doing them sober, but i choose not to due to anxiety on psychedelics/me having enough ideas as it is/stimulants give me more awesome ideas anyway.
tl;dr- stimulants are underrated when it comes to art. they inspire you, disinhibit you, and most importantly, don't impair your motor skills so much that you can't MAKE ART.
(i'm mainly referring to drawing/painting here, i know art covers more than that and what i say may not apply)
Also, psychedelics, delierants, depressants and opioids are all associated with a marked decline in basic, reality based congnitive function, but stimulants can leave more or less able to do things like math, drive a car or use a computer without fucking up. so if you actually want to make art that sober people will appreciate, try stims.
edit: tl;dr, stimulants are an underrated drug for art. boost confidence and bring the ideas out of your own head rather than having to fake creativity on psychedelics. they also don't impair your motor function. this is important for most types of art if you want to make something that people appreciate sober, try stims. because all that matters when i'm high on psychedelics (mdma at least) is bright colours. high people are not exaclty a critical audience. they won't give you the criticism you need to advance.
that is, if you want to be a serious, successful artist (sellout!) or a ~free spirit~
your choice, ultimately.
also, to answer your question- if you have to ask, you know it's true. you've basically told us "i am an addict that justifies it by saying i do it for art" and i can only speak for myself, but i prefer people who can just say "i am an addict" and not justify it. even if i didn't respect addicts, i'd still respect you more for owning up to it and not deluding yourself.