Ya i agree. I hear this all the time. Never bothers me at all in fact I like it get out of my way. Once my headphones go on I don't notice a thing around me.
I disagree. You can be extremely focused on your workout and the behavior of others can still be an irritating distraction. Just from a practical standpoint, people who are more interested in selfies and texting frequently occupy machines for long stretches of time without using them. Today was my leg day and I used our apartment building gym instead of my "hardcore gym".Just like anytime I workout here on a weekday after work, it was an unusually irritating workout. Casual gym-goers are especially lacksadaisical with leg equipment and that just doesn't seem to be the case at any of the more fitness focused gyms I have worked out at.
That's just from a practical standpoint. Getting an effective workout is largely about getting into a certain vibe. That vibe is different for everyone. Some people are able to get into that vibe easier in fancy fitness centers, others find it easier to get into that vibe at more hardcore gyms.