I would have to disagree completely with you.
First of all, if a file host is offering their services free for uploaders, then the only source of revenue is downloaders.
Not really the only source, there are others, whats your point? even so, the filehost owner is still making money from ads in the download page, unless you go the mediafire way, which none of the current ones do. And see, mediafire has pretty nice download speeds for free users, its a quality host, people still buy premium in mediafire for what they offer with the premium, not just heavier uploads and no waiting downloads, they offer much more. If you can't come up with things to improve a file host and let it only be a simple file host, then of course you will have to ask the question of how to drive premium users because its not attractive or different from the rest. Whats the problem? most filehosts are run by 1 to 3 guys who just decided to rent a few servers with no vision or imagination whatsoever, thats fine by them, but the standard will be lower, go cloud, mobile device integration, mobile streaming for premium, and more features and you will get users paying for it. Otherwise, dropbox, sugarsync, mediafire, evernote would be drowning in bankruptcy, yet, they arent, because they are not simple filehosts or online storages with 0 features besides upload/download, they provide much more and you can get decent file storage for free, even rapidshare rocks.
That being said, if the speed is too fast, there is no incentive to pay for any upgraded service.
There is, tier 1 countries have awesome internet speeds. You know what pisses me off? having to download at mediocre 128 Kbytes when my speed can go up to 2000 KBytes and it still pisses me off going at 500 Kbytes but i can deal with that, i will simply stop the download, and get a rapidshare/mediafire, or a host that gives more than 400 Kbytes. Also, premium incentives, see mediafire. The same reason dropbox, sugarsync can sustain the massive amount of free users and space usage for no charge, they make their premium desirable by adding features that integrate nicely with a "file host".
Its nonsense when you have to use bit torrent to download something faster because x file is on a crappy file host capped at 120 KB/s. And even more nonsense is these filehosts that when you try to download come up with a message saying "no more free download slots", pleease, thats just garbage.
You mention 300 - 400 KByte/s is borderline, but this is quite a bit higher than most media is encoded at (meaning faster than real time). Why would anyone upgrade?
People with good internet speed do not want to download 640x480 video encoded at 800 kbits with 128 kbits of audio. They want 480p or 720p or even 1080p quality with a higher bit rate, because they simply have the internet connection to do it, and guess which tiers have such internet connections. Real time is completely useless in here when you can't stream from filehosts, if you are talking of a video site, then sure, otherwise its completely useless, because the user still has to download the whole file, making any "real time" comparison useless. Tier 1 countries are mostly already developed countries with a good/strong economy, good internet connection, good computer hardware, good computer monitors. If a filehost will give me crappy download speeds then i wont even consider it, because i know its a low quality host. I upload files from time to time, and i want my users to be able to download these files in a timely manner, not at 50 KB...
Also, the use of file hosts to distrbute copyright material is a seperate issue and the model of rewarding 'free' downloads is not really apart of this discussion either.
Keep dreaming. File hosts surely proliferate because people upload their own created files and filesonic went to the crap because of legal files and megaupload was closed down because its business revolved around legal files. It is not part of the discussion so end it there, but its a part of the issue in case you had not noticed, pretty foolish to say its a "separate" issue, when its not.
Assuming 300 - 400 is the correct number, then another question to ask is, what would incentivise a downloader to take up the premium service at all?
Well, right now, considering the low quality of the newly freshly started filehosts and how their business has the FBI scrutinizing all over the place scaring all host owners, a simple file host is not desirable whatsoever besides the already stablished ones, like rapidshare.
If it offers good speeds and a little more than that of course, then its a statement of quality and that they can and will do the best to maintain online and last more than 6 months... But seeing how they are exact copies of each other where you can get a script either nulled or for a few bucks and start up your own filehost, credibility is just low unless the filehost comes up with something else than upload/download or starts offering good speeds as it increases its user base, otherwise, its the same plain thing.
If the owner does not want to invest on its own and escalate in quality, then i wont shed money for it. Sure, you have to start low and stuff, but not many increase the speed for free users or quality after they have their own share of premium users putting money into the host, they just keep all the profits for themselves (sort of like AT&T not upgrading their cell towers and instead capping users).
That business of a simple file host is like the old pyramid scheme of autosurfs and pay to click/read and hyip. You start the business, the first users profit like crazy by getting a huge downline of sign ups and downloads or even just the owner profits for a few months, then the filehost goes down or simply does not pay, how many times has that happened now? (: Funny how each new file host has its whois info dismantled and traced to see if its a past scammer.
You want to stand out and be popular, have a huge userbase, you need quality, sustenance, reassurance and vision, 50 ~ 100 KBytes wont give you that.
