Because it is an entertaining 4 minute clip. Same reason why Casey Kasem's tirade was popular. It's fun. Kimmel's recreation of the event was good too.
Next thing you know, some people will say that having giggle fits is unacceptable too. Which would deprive us of the best part of blooper reels. Fact is emotions swing hard on movie sets due to the pressure. It is not unexpected.
Pretty much any non-office job. Any service industry job, any high pressure jobs like the legal profession (lawyers only, not staff!), any kitchen crew, all of these have venting of frustrations as part and parcel of what is acceptable. Mind you it has to be seen as harmless, like Bale's tirade was.
This is nothing unusual. Actors are trying to produce a particular emotion, and if something is interrupting their ability to do that, well, that happens. It is no different than Lawrence Fishbourne telling the audience member to stop talking on his cell phone. Well, it's a bit louder. Bear...