Not a 'reason' so much as an excuse. For as much as I love it, for as long as I've known about it, I've questioned if Bricks and Pieces is profitable. I think it's the best kept secret in Lego, and I don't think that's a coincidence. I don't think Lego ever had any reason to promote it, When it went down, and it often did, nobody seemed in any type of rush to get it back up. Even without the Corona virus I've wondered if it was just a matter of time before they removed the option to buy entirely.
And of course, I have no idea why corona had to shut bricks and pieces down in the first place. Without the benefit of seeing the facility, it doesn't seem like the type of operation where people would be on top of each other. With gloves, I won't expect the virus to spread on the Lego. Seems like 1000% safer than working at any place one is actually dealing with the public. At times like these I think we need to find MORE ways to employ people in internet based retail.
Trust me, I feel bad for putting that question out into the universe. Bricks and pieces is the best.