It is a challenge for many offices to properly give HR duties the bandwidth it deserves.  With the best of intentions, it's still difficult getting the partners or project managers to be available and attentive for an hour--despite the best efforts from the HR rep.

That said, any office that is in need of good help must recognize how off-putting that response can be.  I would suggest you keep looking.  Those firms that treat perspective employees like perspective clients are few and far between, but they're worth waiting for.  Good luck. 

Showing up late:  how late are we talking about?  If within 10 minutes I'd say that's pretty much on-time and doesn't need a remark.  If more than that it would be nice for the late person to apologize briefly.  If they're going to be more than 20 minutes late they should try to get in contact with you and give the option of rescheduling.

Looking at phone:  I don't think this is a big deal if they're not the only other person in the room with you, and if it's very brief. There can be important reasons that they'd want to keep an eye on messages and you'll probably need to get over getting upset at this, as it happens in most settings and professions these days.  If they're the only one meeting with you there might still be some urgent reason that they may need to glance at their phone, but it it would be nice if they say "excuse me for a moment".  As long as they're not doing this several times and/or for a long time while you're talking, it's not ideal but not inexcusable.

Taking away opportunities because candidates follow up every few days:  I'm totally on their side of this one.  Following up every few days is highly annoying, and would signal that that candidate will be a needy and demanding employee.  I'd move on to the next candidate if I got that many followups that close together.  It's the candidate who is rude in that situation.  Follow up once within 24 hours of an interview, to say thank you, and then once a week or two later.  Any more times beyond that should only be attempted if they encouraged it or said things to lead you to believe they'd be coming to a decision around a particular date.

"Dragged into an important meeting" unfortunately happens pretty constantly, particularly for managers and principals.  If it's really unavoidable and can't be postponed then they should take the time in that situation to contact you and tell you they'll need to reschedule.

These things are not unique to architecture.  You have to get a little thicker skin for some of it, while too much of it is a good indication that you want to avoid that particular employer.

Thank you for all the honest comments, genuinely appreciate it.

It depends. Interviewer 10-15min late? Fine. Things happen. I’ve had them be a hour late with no notice. That pissed me off.

I see people look at phones all the time during meetings. More often for internal ones. It’s annoying if they’re ignoring you, but things come up, especially with more senior people who manage multiple people and projects.

Not answering a post-interview, negotiation call has happened to me. I think the important thing is communicating they can’t make the call, even if it’s a text or short email.

What you’re experiencing isn’t uncommon at employers in general. Things come up. Some people suck. How you choose to deal with those situations can be the difference between getting a job you want. 

I could definitely make it work, it’s just that part of me wonders if it’s their way of stepping all over me. You let it happen once and where does it end? But I get it, welcome to the reality, pick your battles/survive.

I really respect how honest these responses have been. Definitely helps seeing other perspectives.