Why is using 4chan on your phone usually frowned upon on the

Because the wider internet started to decline around and after 2007 when the first properly internet capable smartphone, the iPhone was released.
First, smartphones and their app ecosystems are a step back from the distributed communities and information the web enabled before. After their widespread adaptation, you might've noticed a decline in website diversity. A smartphone user represents the internet user who never steps outside the commercial datamining controlled censored curated circle of websites commonly referred to as social media.
Second, mobile phones decrease the barrier to entry for everyone. Previously you'd needed to be able to operate and own a pc to reach the web, and it should be clear to you that smartphones are far easier to use than pcs. This results in the decrease of general literacy everywhere on the net. Smartphone users represent the users who don't know anything about technology or how to navigate the internet.
Now, these two user groups overlap to a great degree in a certain demographic, children. Those who post here in class with their phones hidden under the desk. They're all new to the culture here, and the site is the most underground website they've ever used. It might be the only one they use a web browser for too, for everything else they have smartphone apps. They've never used irc, have never downloaded a torrent, can't see filenames or use source links and have nothing to contribute except for e-celeb and smartphone threads. This is the general stereotype for phoneposters, and it is for valid reasons.

This post was written on a phone, by the way. You should still judge a post by it's contents before anything else.

>>1517677
Dumb phoneposter

>>1517692
ebin x-DDD

There are quite a few reasons, you should probably figure some out by yourself if you think a little.

Same reason people say "GO BACK TO REDDIT!"

They desperately want to fit in.

>>1517928
t. phoneposter

>>1517926
I honestly can't think of any

>>1517952
Fair enough, I can give you the benefit of the doubt.

I don't phonepost bash that much as the individual case is more important then the means it was delievered, but I'll try my best.

There are few things from top of my head.

Phone as a devide to use 4chan over desktop alternatives will have some disadvantages. The longer posts are harder to read as many phonescreens can't encapsulate such posts into the whole screen, so you awkwardly use your hand to read a single post, discouraging to engage with posters that create longer posts, which in general are probably more quality posters, then creating posts on phones are way more difficult than on desktop, as any revisions and corrections or proper quotations and replies are just rather difficult to achieve, leading to phoneposters possibly being led to read shorter messages and create only shorter messages themselves, which will likely lead in lower quality of 4chan in general. I'm not suggesting that you cannot bypass the whole problem if you're a good poster, but a chunk of phoneposters might be affected by such phenomena, making phoneposting potentionaly undesireable by some 4chan users.

Then we have the fact of how people interact with their phones/desktops, when browsing desktop there is higher commitement than with phones, as phones are often just used for a few minutes when riding a train, taking a dump or just waiting in your dentist's office, which just doesn't seem a kind of posting enviroment that would encourage quality, it'd more likely be some off cuff random short post/thread that really doesn't contribute much as the poster isn't paying that much attention in general as opposed to desktop user.

Another issue is that mobile I.P.'s are too unstable and everchanging that they get abused quite heaving to ban evade/shitpost and message bot. Sure, it's not too difficult to reset your modem, but jsut going into plane mode is entirely different league.

There's more, but I don't have enough space.