You guys are taking this to an extreme that doesn't really reflect reality. Yes, there is a higher usage of relievers which means less value in starters in general, however, that just means that there is even more emphasis placed on finding GOOD starters because no one has enough relievers on their team who can eat an entire season's worth of innings for a team year in and year out. The fact that there are so few starters who throw 200+ innings nowadays just means that there are less AVERAGE starters who are being left in for too long to "eat innings"; it doesn't say anything about the value of GOOD starting pitching which will always remain a premium. The Washington Nationals just won a World Series with Scherzer, Strasburg, and Corbin putting up 6.5, 5.7, and 4.8 WAR seasons playing against a team who's best starting pitcher signed for over $300 million as a free agent with the Yankees - so where exactly is this notion of starting pitching being "less valuable" playing out in reality? The drop in HS pitching going in the first round doesn't really say anything about the value of starting pitching in general, as HS pitchers (especially right handed HS pitchers) have ALWAYS tended to "fall" on draft day - that isn't a new trend, it is probably just emphasized nowadays by the fact that College players in general have gotten better (as you mentioned).
Shifting to the discussion at hand; from a pure baseball standpoint I fail to see how a Type-1 Diabetic who has never hit for in-game power (Mitchell) is any less risky than a guy like Hancock who realistically was a 1-1 talent who might only be getting to us because the situation at hand meant that he had a few bad starts and then the season ended. The same can be said for Veen who obviously carries added risk due to being a HS player, regardless of how nice his swing is. In the case of Veen, there is also something to be said about the timeline of our team/needs when looking at a college pitchers vs. a HS position player. That fact would be negated if Veen was legitimately just a better prospect than someone like Hancock/Lacy, and if you feel that way its fine, but that isn't something that is considered to be dogma within the actual scouting community/front offices. Obviously there is also the hypothetical of getting Veen underslot or whatever, but that is a different discussion altogether. Either way I don't think we can really f*** this up no matter what which direction we go.