First rule of #warframe:
Don't listen to the negative Nancies. If someone insists on telling you how a part of the game or a specific frame is bad, smile, nod and then ignore them, as they're either unflexible and bitter or just don't know how to play.

Try things for yourself, form your own opinions and play the game how you like it, how it's fun for you.

@ulvra One of the things that's kept me playing for as long as I have is how pretty much anything is viable up to the mid-high levels as long as you have the right mods ranked up.

@Forgebold Aye, definitely, but even then I find that there isn't really anything like a "bad frame". There's frames which doesn't fit your playstyle and there's frames which are dated, but the latter are usually the ones who will soon be revisited.

One of the first things I was told when I started playing was how Mag was crap and that's a bloody lie. It's all about how you play.