Apparently Mr Martin was named after Guy Gibson and can be a bit incoherent when he gets excited, but he is definitely passionate about the things he does and has a great respect for those who he describes as having proper jobs and doing real work see his series "How Britain worked".
As said there are better factual programmes on Discovery and other specialist channels but they would not get aired on prime time TV as they would not attract enough audience figures.
As for shooting up the BMW you can blame that on the Top Gear factor. The producers are trying to cover all the demographics, the nerdy types will watch for the rivet counting, then there's the nostalgia factor which will bring in the oldies, the ladies will watch because Guy's on it, so how do we get the lads to watch it, hmm I know we'll shoot something to bits that'll do it.
If it gets people interested then maybe, just maybe they'll watch more worthy programmes in future, but don't hold your breath.
As for the IWM going all corporate. I'm afraid that that's the way that they run all these places nowadays. The greater proportion of people at the top end are not restorers or curators but people who are skilled at climbing the greasy pole. That type doesn't give a fig about what the company does as long as they can tick the boxes on their CV's and get the maximum personal advancement. The Science Museums treatment of Wroughton is a classic case of this.