One must not face the Qibla when taking a dump, unless covered by a screen

Bukhari Volume 1, Book 4, Number 146:
Narrated Abu Aiyub Al-Ansari:
Allah's Apostle said, "If anyone of you goes to an open space for answering the call of nature he should neither face nor turn his back towards the Qibla; he should either face the east or the west."

Bukhari Volume 1, Book 4, Number 147:
Narrated 'Abdullah bin 'Umar:
People say, "Whenever you sit for answering the call of nature, you should not face the Qibla or Bait-ulMaqdis (Jerusalem)." I told them. "Once I went up the roof of our house and I saw Allah's Apostle answering the call of nature while sitting on two bricks facing Bait-ul-Maqdis (Jerusalem) (but there was a screen covering him. ' (FatehAl-Bari, Page 258, Vol. 1).

Volume 1, Book 4, Number 150:
Narrated 'Abdullah bin 'Umar:
I went up to the roof of Hafsa's house for some job and I saw Allah's Apostle answering the call of nature facing Sham (Syria, Jordan, Palestine and Lebanon regarded as one country) with his back towards the Qibla. (See Hadith No. 147).

Wow... Mohammad had rules for everything...

The question is, do modern bathrooms come with a screen? Are walls considered screens? If not, do Muslims have a claim of religious discrimination against engineering firms who constructed buildings so that when one answers the call of nature, they face the Qibla?

Why was it necessary to include 'Abdullah bin 'Umar's version of events. In that situation, Mohammad faced Jerusalem, breaking his own religious edict. Did Bukhari include "Volume 1, Book 4, Number 147" and the part of Mohammad using a screen as a way to justify everything Mohammad did, even when he broke his own rules?

Why were Abu Aiyub Al-Ansari and 'Abdullah bin 'Umar watching Mohammad take a dump? Were they the original religious voyeurs?

Why was Mohammad taking a dump on his roof? Was this a reverse chimney?

If Mohammad was the role model for all Muslims, shouldn't all Muslims have people watching them take dumps, and shouldnt all Muslims take a dump on their roof?

Finally, what religious reason exists for mentioning the fact that Allah's Apostle answered the call of nature while sitting on two bricks? Does this mean all muslims should sit on two bricks? Or is this another example of Bukhari poking fun at Mohammad?