My point is that Clarkson is worth more than MacD. Or at least he has less negative value.
So you don't actually have a point then, since the above isn't even close to being true. One of them is a serviceable, albeit overpaid, NHL player. The other isn't even physically able to play in the NHL, and if he was, probably would be continuing to sit in the press box.
MacDonald, if he continues his play of the last 30-40 games, may actually draw himself into the conversation to be selected in the expansion. Laughton looks underwhelming so far in his admittedly brief stint, and a new team will a)need to make the cap floor and b) need some veterans instead of just scalping every team's young players, which is what everyone seems to think will happen.
Even if you wanted to assume that the two are equally skilled (they aren't), MacDonald has the benefit of A)not needing to be protected, and b) his contract can actually be bought out. Clarkson's can't. So while its nice to think that his LTIR eligibility (however long it lasts) is a bonus, keep in mind there is no LTIR in the offseason, and speaking from experience, having a dead contract on your hand can really handcuff you when it comes to trying to make off-season moves.