While I agree that it's the main job of the hosts to present the information about the products (and it really bugs me when they don't), I've begun to wonder if the management has placed so many other off-air duties on them they don't have the time to devote to product homework like they used to. Podcasts, social media, "entertaining" on air, etc.
As for the colors, I saw a previous presentation of NFL shirts with Alberti and it was the NFL vendor representative that started making the different shades of red, for instance, into a big deal. He said that many teams may have red in the team colors, but each red is not the same. One of the things that set their products apart from those not endorsed by the NFL was that each team's colors were authentic. And he compared some of them. Alberti was only doing the same thing. To a real football fan, that matters.
Along with that, I think many of the hosts that remain today just aren't "into" football like some of those that are no longer with the company. It's the same with hosts that obviously personally use a product they sell as opposed to one that doesn't. One can point out a lot more intimate product details and information than the other.
ETA: For those interested, here is what former host Dan Wheeler posted on his FB page...
A week from tonight I will be at QVC to kickoff an amazing NFL Today’s Special Value at midnight eastern. I’ll then be on throughout the day next Thursday, September 12th. If you are a Lions fan you had better be tuned in at midnight as they sold out early last year. Find the perfect gift for your NFL fans who want to wear their team colors in style. See you then!