The only times I ever have a hard time with infiltrator is on waves 40+, as that’s when enemies start doing enough damage to literally rip your stim apart in 1-2 seconds. You almost have to start playing a bit more conservatively then, but other than that, the class is absolutely nuts.
I’m not the type to care if someone kills an entire wave on their own. I’m admittedly guilty of doing this with Fahz on occasion.
Never had anyone ask me to stop, so I’ve always assumed most people enjoy me soloing a horde match for them lol.
I’ll have to keep in mind that not everyone may enjoy that I suppose.