not really a big issue these days
It may not be a big issue for the tech savvy or committed.
But it is a huge issue for the broadcaster, who wants a simple "click to listen" hyperlink.
It really should be as simple as that, and I have a lot of sympathy with the OP - the average user is far too impatient (or wary) to read instructions, download and install yet another media player, and paste in a URL before
they can decide whether they like your stream or not.
The problem is not just with mobile devices, desktops/laptops are almost as bad - some media players require the .m3u extension, some require it to be omitted, some cope either way, some change the requirement between versions. A Flash player can be a good solution for desktops but is useless on mobiles or iDevices.
A default media player that does not support streaming is one thing, but the lack of standardization among those that do is unbelievable.
I started radio broadcasting in 2005 and have always had to offer multiple solutions. With the exception of more recent versions of QuickTime Player, every solution I have implemented for the various media players (those that do actually support streaming) has had one thing in common - a simple hyperlink to the stream using the HTTP protocol - and they can't even harmonize that.
It should be so much easier than it is.