While the contract numbers are high, there are teams that would still have made it work somehow for a Doughty or Kopitar trade. You'd have to deal with the different NMC stuff so that makes it more difficult but , yes, Blake could have traded them if he was planning on flat-out sucking for five seasons or more: he's not.
We've talked about how the DL rebuild was different in the sense that he already had his #1C waiting for him in Kopitar. He thought he got his goalie in Bernier but he already had Quick waiting for him. He had Visnovsky but immediately moved to get Johnson and then was fortunate to get Doughty so he moved on from Viz. As far as wingers, he went out and got O'Sullivan and already had Frolov, Brown and Cammalleri.
What about Blake? It's already been said numerous times that Blake was dealt a worse hand than Lombardi since Dean inherited 11/23/32 and he didn't have the contract issues. Not arguing this fact. So where does that leave Blake? Well, Blake did inherit a team that went to the playoffs in his first season with a #1C that won the Selke and was a Hart finalist along with a #1D that was a Norris finalist. Everything goes to shit the next season, Bluc says they are rebuilding and Blake proceeds to move out basically every veteran but he keeps the teams two best players, knowing that they will pay them a ton of money for 2-3 seasons of suck. Why?
Well, sucking doesn't guarantee that the lottery picks wind up being Kopitar or Doughty level talents. If you believe that these two guys are going to still be top performers through the end of their contracts, why move them just so you can *hope* to sign a UFA of their caliber (will cost more than their current cap hits and won't be 23 years old) or *hope* that the picks/prospects you get are amazing? You already have to do the latter so why don't you hedge a bit by hoping the picks/prospects are amazing and can be added to two guys that, face it, are legit 1st line/1st pairing guys.
Blake has supposedly put together the best prospect pool in the league. He now gets to start adding these guys to a team that still has two very good players at 1C and 1D. He still sees these two as part of the solution. COVID and flat cap can change things since you'd usually bank on their cap hits being minimized by a rising cap but, even then, the team has so much space even now and Kopitar's contract ends in three seasons.
I think your stance on this depends on if you think Blake's first concern is making 11 and 8 happy. I'm not a Blake fan but I don't think I can accuse him of this: I truly believe it is a hockey decision. If he moves a bunch of young assets for some 30 year old guys then I'll say it but if he moves some unknowns for a sure thing in their mid-20s, that just seems like the natural evolution of a rebuild as you move some lottery tickets into actual dollars. You don't trade in all of your lottery tickets though and that's where Blake is going to have to prove himself.