How are you safely going to get to the hard shoulder in the event of (say) a blowout when the traffic on your left is over/undertaking you at 70mph?
Er this is such a strange remark (although not an unsurprising one given the general standard of posters on this forum) I genuinely do not know where to begin.
If you have a blowout on a motorway you would hope that those around you are aware enough to give you space etc. regardless of their speed or road position. In Australia and the US where overtaking on the inside is allowed I have never seen any issues with it causing any problems (quite the opposite), but then I will grant you that, on average, drivers in those countries are generally better than those in the UK and have less of an ego to boot.
Most UK drivers could do with a lesson in manners, patience and road sense! The nonsense posted on the joining a dual carriageway thread is a very good example of everything wrong with driving in this joke of a country!