Flying IFR is easy under normal circumstances IMHO. It is even easier for airline pilots - for example I flew from London to LA on a B747 recently and the amount of time spent in IMC was oooohhh....Nil. I've flown my fair share of light singles and multis without AP and basic instrumentation and enjoy it. I wouldn't do it for 600 miles though, but a hop from Jersey to Bournemouth---no problem.
I just don't know why there can't be a "PRIVATE" and "COMMERCIAL" IR (or my preferred wording "not authorised for public transport ops". For the Private there should be training as required to pass the flight test, one exam, and credit for previous instrument time (for example then the IMC time would count). The flight test could be to the same standards too.
Requirements for the "commercial" IR should be a formal course and exams OR a Private IR already held and some other stuff.
It really is so easy so I just don't know why this won't happen. I suppose it is a function of being in europe , with too many people who will never agree.