The point is because the DVD serial sets are out of print and some are ridiculously expensive. BBC isn't making money from that and who wants to pay those prices and devote shelf space to all of those serials. They are way overdue to give us entire seasons on blu-ray.
They're sort of cheap if you know where to look. If you can play region free DVD's it would be a help. Only thing is the US & UK artwork is different. When I first started buying them about 15 years ago they were fairly expensive. £20 for Pertwee's debut. As years went on I was getting most of them for around £7.
Second hand places are a help. I get the odd one in CeX but I've noticed prices starting to rise again in the past year or so.
I lost about 15 stories on a recent move which was a bit of a pain in the arse considering they were in perfect condition. I'm going to rebuild it again. I could just download them but I like the extras.
The production subtitles on each release are great. Never bothered with commentaries on any DVD. Who or otherwise.
I wouldn't say the Blu-Ray boxset are long overdue. They're producing them at a large cost and bit making a lot of them. The Baker set sold out extremely quick so that prompted the subsequent releases that are on the way but if they don't sell well they won't make any more.
I'm really sceptical that every series will get a release. Baker will sell well because that's the Doctor from the classic era who is in the public consciousness the most. He's one of my least favourite but unfortunately I don't see sales of the series with missing episodes or the Colin Baker/Sylvester McCoy eras selling as well.
I couldn't care less about the HD quality. It wasn't made for that I'd much rather the arsehole who stole 'The Web Of Fear' episode shortly after the whole story was recovered would hand it back. And for all the other episodes that private collectors are hoarding to be shared.