We've discussed this a number of times before in this forum.
The actual file size of the media is magnitudes larger than when you're working with images and other blog file attachments. File uploads are set to size limits that is unpredictable, this is a product of PHP itself, not our app or WordPress. Most hosting companies use 2MB, some will allow 5-10MB. The average audio podcast is usually 30MB in size, video is in the 400MB+ size. Providing uploads for such large files is just not possible without being the administrator of your own web site. And if you are, you know you do not want to increase your file upload limit do to it opening up possibilities of Denial of Service (DoS) file upload attacks.
We provide a plugin that works consistently across all web hosting providers. In order to provide the same experience for all WordPress hosting providers, the handling of uploads is left to the hosting company. Usually they provide FTP.
Keep in mind you should not host your media on the same server as your web site. Learn why here: http://create.blubrry.com/manual/internet-media-hosting/
If you're serious about podcasting, you're not going to host your media on your web site in the first place.