It is a shared entrance and one of the tenants displayed the flag. 

Also, having privacy in the back or even a view adds to the value.They are an economical hotel alternatives for families and especially popular now during Covid since they have private keyless entrances.

The plan is to finish the basement which has its own entrance to make another unit available.

Maybe, we get 6 to 10 phone calls every year by having our phone number at the entrance of the building, but that tiny inconvenience for having to answer a few phone calls makes us feel that we are doing what we are supposed be be doing to make sure the building is run properly.

Now that I have the report I see that quite a bit was missed (leak in the main drain line in the basement, water in bathtub is not going out, kitchen sink is leaking, rear entrance doesn't have a step, loose guardrails in the basement and on the upper level, windows not operational).

There should be a separate entrance for all 3 structures.

Is the barrier to entrance just too high?

I actually plan on house hacking it, it has a separate entrance.

All of these units would have separate entrances and no hallways, no shared central heat or air, no shared bathrooms, etc.

Upstairs tenant empties a can of wasp killer into the entrance.