Come on, are you really that naive? Big companies didn't want to endorse either side, because they knew it would alienate 50% of their customers. I'm actually surprised that any retail business (and I include High St Banks in that) came out for either side.
Sort of as with Tesco, Morrisons and Sainsburys not even the current management of the companies endorsed either side. With Lloyds Banking Group I am told there is more to it than not wanting to alienate customers, the current chairman Lord Blackwell has many times said before and after the EU Referendum that the EU needs to have major reform and that the current arrangements would be ultimately unsustainable.
But coal mining was an unsustainable industry anyway, especially when imports from China etc, are a lot cheaper.
As for Fishing, the EU measures are ultimately there to preserve the Fish stocks, as we were previously overfishing.
Teeside needs better, more sustainable jobs, like car manufacturing, which the EU provides through single market access.
Don't forget that Hitachi and Nissan have plants in the area.
Sort of with steel in particular one of the problems was that the UK market was being flooded with Chinese state subsidised steel at a price British steelmakers couldn't compete at. In this situation the most logical thing for most countries would be to either 1) give state aid 2) increase tariffs on steel imports but EU rules prevented both of these from happening.
The single market has been a mixed blessing for manufacturing, back in 2011 I remember when the Class 700 contract was being awarded and it was controversially given to Siemens who were building trains in Germany rather than Bombardier who were going to build them in Derby. The Government stated that EU law required this to happen.
With train building in particular think about it by 2005 the United Kingdom was down to one train factory (Bombardier Derby) and most trains were being built abroad, Newton Aycliffe of course opened in 2015. Since the EU Referendum however CAF has announced a new plant in Newport, Taglo has announced a new plant in Longannet, Siemens has announced a plant in Goole and I think there might be more things happening with other companies. I would imagine that building trains in the United Kingdom will now be a factor in awarding contracts for trains post brexit.
Don't get me wrong I do understand that the Single Market has benefited companies a lot and leaving it will create a lot of uncertainty. However at the same time the EU single market does have its flaws which given that its the EU they weren't going to change.