Sure, there's also tons of busts. It happens. The Rockets are saying it via their friendly press outlets, not because they don't think that there's any chance to find a good player, but they don't want to put up 3 more 20 win seasons to find out if they did.
The odds of drafting a total bust (i.e. a player not good enough to start for an NBA team) are actually relatively low in the top 5 of a draft class this stacked at the top. In a weak class, sure, you'd have to be a lot more worried about it. But the consensus seems to be that this is a great draft at the top.
Sure, the odds are lower this year because of Victor. But historically, draft pick value drops precipitously outside the 2 or 3 range, though that may flatten out over time since variance will presumably go up due to player age now. Anyway, I'm just relaying to you what has been reported by Iko and other team friendlys - drafting 19 yo is a crapshoot - outside of a select few like Victor - and after the last 2 miserable years, the Rockets (aka Tilman) don't feel like waiting around a few years for yet another 19 yo to learn on the job (especially w/o control of their own draft for most of those years).
Scoot is talked about as a prospect that would go #1 in most drafts. I already know what you're going to say, that "there are always guys like that" etc, but I personally have not seen that. Analysts and scouts are regularly comparing him with rookies and young guys already in the league who have already demonstrated they can be productive starters and still saying "I would take Scoot". After Scoot, there are more questions, but I personally have never seen an athlete as good as Amen Thompson since I started following the draft. The hype surrounding him would be ridiculous if Wemby and Scoot weren't there. The way he moves on the court is just mindboggling. And, I don't personally agree with this, but a lot of people are really in love with Brandon Miller's game as a shooter, and I think there are at least one or two classes in the past 10 years where he could have gone #1. I general, I've heard a number of people talking about this class like it's ridiculously good in terms of athleticism and has a very strong lottery group. This has a chance to be the best draft since 2003 and you don't just give away a top pick in that kind of class for some B-tier star. Remember: Rookie contracts are the most valuable contract in basketball.
All jokes aside I think Christopher is one of the players who could gain the most from a coaching change. Udoka may be able to unlock his defensive potential (strength and quickness) which I believe was one of the reasons the rockets drafted him.