You could assign value to wins based on how many opportunities a given rider has to win in the year. A sprinter has more opportunities to win a race than a pure goat, therefore the value of each victory is less by comparison because a multi-col odyssey victory like, say, Nieve in Rifugio Gardeccia, is one of maybe 5-10 race days in the year that a rider will take on (few of which will be as hard as a Giro queen stage), whereas sprinters can take on 40 or even 50 stages that could end in sprints (most won't of course, but it's theoretically possible).
The other value is related to that particular race FOR that type of rider. A GT stage is a high profile race, but a GT stage for many riders is part of a tilt at their season's overall goal; a GT stage for a sprinter is another stage win, just in a slightly bigger race. There are dozens of puncheur finishes in the year, but winning on the Mur de Huy means more than them because it's the most important Murito of the year. Likewise, for a sprinter, the Champs Elysées is more important than any other Tour de France stage (notwithstanding that you must make it to the end to get there of course).
However, sprinters don't deserve the opportunity to fight for the win unless they've had to do some work to deserve it. I don't mind if they survive some obstacles or the race is hard and burns people off, if you've made it to the end you deserve the right to fight it out for the win. What I don't like are the total gift days, when organizers almost go "well, let's have a day for the sprinters" and just lazily drape a race parcours over some featureless roads.