Well some people like to collect devices on the front of their bike like it was a pawn shop. I like having just an iphone. tunes, phone, map, speedometer, etc.
Which is why some of us use tools designed for the job. I have a Zumo 660 that does everything you mention. So instead of half-assing my navigation, music, or phone, I use a piece of equipment designed for my needs. I don't require cell service, and if I do something that breaks my GPS, my phone still works.
Using a phone on the bike's "dash" works in a pinch, but serious users need to spend a little money and get the proper equipment for the job.
It's certainly your choice if you want to spend $600 plus dollars on a Garmin Zumo. However, there are some that don't . Personally, I have found that using an iPhone with the Navigon app is workable for loading pre-programmed routes. I ride with a group that some have Garmin Zumos as well, and they are just as susceptible to having "issues" with pre-programmed routes as the rest of us. I don't believe it's necessary to denigrate anybody that chooses not to lay out $600 as "half-assing", or not being a "serious user".
Don't get your hemorrhoids in a bunch. I wasn't "denigrating" anyone. I was saying I choose not to half-ass what I do. Using your phone with a navigation app is "workable" which is saying its half-assed. I ride in all conditions. Sun, wind, HARD rain, snow, cold, warm, whatever. I have depended on my GPS more than once to route me through an unfamiliar city in a downpour. Do that with your iPhone, and you'll be out $600 anyways. Ask the IBR guys, the 'serious users' how many of them are depending on their phone for their navigation. I bet none of them is.
I have half-assed plenty of stuff that I knew I could get away with. I choose to not do that on my MC with my navigation. I also back up my GPS with hard maps. Without those, a GPS can be useless...but I won't go into it as I don't want to hurt any feelings.