In windows phone world, if you have:
IM problem: who use IM? SMS is the way to go
WiFi Issues: why don't you have unlimited data?
No Instagram: who uses Instagram?
Lack of Apps: quality apps, no fake, no justin beeber apps in WP
And so on and so forth...
And in iPhone world if you have a bigger than 3.5" screen you cant use it with one hand, unless its an iphone5, then its okay, and perhaps if apple releases an iphone with a bigger screen, but lets cross that bridge when we get there, until then NONE beyoned 3.5" (4" if iphone5) are useable.
Also in Android world, if you cant dualboot two custom ROMs as well as track and kill Osama as well as navigate a robot through an obstacle course using X-term its not a real phone and is merely a poser.
Thats just how things are. People defend their choices to insanity and beyond sometimes.
As for your little list, my personal responses are simple.
IM Problem: I dont have one, and it sucks that you do. Either find a workaround until its resolved or change phone.
WiFi issues: get a replacement handset, yours is faulty. Mine does not have issues, nor do most.
Instagram: Dont use it myself as I have no idea what the appeal of it is, but I would love it if it came to WP since instagram-users would be more likely to try WP8.
Lack of Apps: Personally Im not appdependant at all, and WP8 does what I want it to do allready. If you lack apps, write to the developers or seek an alternate solution, alternatively change your phone to a different OS if the benefits of said app outweigh the benefits of the OS contra the OS that has the app.
Fairly simple logical stuff Id say.