Isn't this a legitimate concern and one reason why many militaries have passed on the bullpup design????
The UK, France, Austria, Australia, and China all use bullpups. There are probably others. Israel is adopting one.
*shrug* I wouldn't worry about that the ejection and whatnot. People shoot bullpup .50BMG rifles all the time.
As for the not being able to do weak-handed corners....
1. With all of our modern technology, we can't make a brass deflector that would allow weak-handed shooting? It'd be a field-expedient solution to those times when you absolutely MUST fire your bullpup weak-handed. (You probably have to do it a lot less in the real world than you do at an "urban rifle" class at a shooting school.)
2. I know that everybody here has a big thing for "urban" fighting and "urban" training and whatnot, as it's all the rage now (it's replaced "tactical" as the latest gunrag buzzword) but the VAST majority of military engagements take place OUTSIDE. Even if you're in a city, hey, you're outside most of the time. Being within city limits does not automatically mean you need a special type of rifle. A soldier in the field just doesn't have to swtich hands all that often, at least, the armies of the countries I named seem to think so. I don't know if I've ever carried my SAW right handed. I view the shorter length of the bullpup as an advantage for getting through thick brush, in and out of a track, and for airborne operations, not necessarily for SWAT-style room clearing (though it'd be handy there too.)
3. Is there any particular reason a downward-ejecting bullpup couldn't be designed, so as to make it completely ambidextrious?
4. Is there some law of physics and science preventing a bullpup from having a decent, service-grade trigger? (Besides, the worst bullpup trigger couldn't be worse than the trigger on my SAW.)