i miss using the Vector, the MP5 or (..) Midas

One single weapon type: SMG.

nowadays everyone is either rolling with shotguns, [riffles] or hunting rifles

Three different weapon types: Shotgun, Assault Rifle, and Marksman Rifle.

Where is the diversity? Shouldn't we as players feel powerful with any type of weapons we find?

I don't quite follow your logic here.

By your own admission, people nowadays are using a more diverse range of weapon types.

Would you prefer that everyone goes back to using an SMG as their primary?

Why oh why Massive has decided to nerf these type of weapons.

My MP7 and PP-19 still shred just fine with the proper weapon mods attached, plus crit chance/damage rolled on my gear, and crit chance/damage from my pulse, etc.

I honestly don't view it as a nerf at all. It's just a slightly different way to deal damage that requires a slightly different configuration to make the most of it.

SMGs are still badass, imho.

But of course, YMMV.