As former cabin crew for Flybe all I can say about this is ABOUT TIME!!
A large number of pax think it is their God-given right to bring everything including the kitchen sink on board then have the bare faced cheek to argue with you when you point out it is too big and compromising their safety and that of the people sitting around them, even when this conversation takes place in a friendly and helpful service-focused manner. This is because such people either think the world revolves around them, are ignorant or simply think accidents never happen AND because BE themselves have been too soft for too long about baggage: far too many crew rely on and use spare rows to stow oversized luggage (hands up - guilty!), which of course pax now rely on to happen. Ground staff are also to blame - they just want a flight to close so the punctuality stats are met, let the crew worry about the baggage.....I had to laugh on my last flight from DUS when I noticed the BE hand baggage sizer was actually being used as a bin for rubbish. I beg you!
The worst route by far for baggage IMO (from BHX) was AMS, closely followed by BHD and DUS (both in both directions). The best - ABZ, where the ground staff patrolled the boarding queues and tagged all oversize bags for the hold. Never had a problem from ABZ even if on a fully loaded Dash.
With the cut in frequencies on key routes, flights are generally operating with a higher load factor (I know this for fact at BHX, can't speak about other bases) so the spare row has is becoming rarer and more bags are having to go in the hold, causing upset and delay.
However, this policy will only work if it is communicated clearly and properly and applied consistently and to all pax WITHOUT EXCEPTION. People think it is their right to break rules and get away with it (in all areas of life not just flying, not just on BE) so hopefully once bitten twice shy....if crew still use spare rows to stow baggage or ground staff turn a blind eye at the boarding gate, pax will continue to bring on the kitchen sink. If paying £25 for a bag to go in the hold is a problem, should you be flying in the first place? If you can't wait 15 mins for your bag to arrive at reclaim, then I feel sorry for you that your life is so busy you have no time!
I don't buy pax ignorance about hand baggage as a lot of BE pax are regular flyers - however BE must make it a lot more clear when booking a flight of permitted bag sizes, relevant charges and on board storage limitations then everyone will be happy.
Despite all of this, lets not forget that the current permitted bag size plus 'under the seat' size baggage allowance on BE is very good for a solo traveller and the size of aircraft they operate. It allows you to carry a lot on board - I have a BE sized 4 wheel trolley (fits Dash and EMB lockers easily) and it fits more than enough clothing for 3, even 4 days away (more in summer when there's no need to cart coats and jumpers around) and my laptop bag fits all my gadgets and personal bits and bobs such as wallet, passport etc. Of course things become more difficult if you have children in tow as well.
Sorry I have gone on a rant but it is an issue that really winds me up (even though I am now SLF!), as it is now the expectation of some to bring your whole life on board in a series of over-sized bags!