You cannot see yourself as superior without creating something that is inferior. "I am on a spiritual path" leads one to see those who are not. "His practice is bad" only exists when you see your practice is better.
Eh well. A quote comes to mind:
The Great Way is not difficult:
Jus don't pick and choose.
Cut off all likes or dislines
And it is clear like space.
- Tseng Ts'an, third patriarch of Zen
The simple act of saying, "I am on a spiritual path," does not imply a comparison with others; it' is a statement of what is, not a comparison.
With that said, however, I'm just not seeing this "aikido is a spiritual path" kool-ade being passed around and guzzled in my admittedly limited aikido experience. There are those who sell it and those who buy it, but I don't personally find it to be omnipresent. In the dojo where I train, it's nonexistent, as far as I can tell. We're also refreshingly free from other assumptions about why people train. This is nice because it saves us from a lot of second-guessing of ourselves or each other: why are we here? Do we have the right mindset? Are we being aiki enough? Am I more aiki than thou? Yadda yadda yadda. I'm heartily glad not to have to deal with all that.
Now, the whole "Is aikido a sport?" thing is reflective of something different, which I had thought was primarily a USAian thing: the need to understand any physical activity as a sport. We do tend to do this in our culture, I think. I don't think of aikido as a sport unless you redefine "sport" in such a way as to be uselessly broad. But it's a false dichotomy to think that aikido has to either be a sport OR a spiritual practice.