Yeah, thats what Monero fanboys (or some of them) seem to not get. Monero will never be as big (let alone bigger, lol) than Bitcoin. Why? its simple, its super anonymous-only features give no chances at being transparent. This kills a large base of users and uses. Plus Bitcoin is king in all that matters: network strenght, adoption, network effect in general... which is all that matters, even more than who has got the best-ever technology.
Also, what people do not realize that if Bitcoin was completely anonymous it would have never been legalized. I'm pretty sure that even if Monero grows, it is going on the black list pretty quick (unfortunately).
I'm not saying that this will kill Monero, but it is definitely going to prevent it from taking a grasp at a larger user base.
However, Bitcoin seems to be in the middle of everything. It is partially anonymous, not too fast, not too slow; with a few upgrades here and there it could be considered
almost perfect (for our time).
Monero/DASH/insert anon coin may not be as relevant in the "real" world, but it could revolutionize the way money laundering, tax evasion, hiding assets, black markets etc work. So it might have a much smaller userbase, but all of those are potentially trillion dollar markets.
I don't see Monero succeeding if bitcoin fails. But if bitcoin goes mainstream, and people start to readily accept non-government backed online currencies, then I believe it is inevitable that such activities will also move to crypto; and it will be an anon coin rather than bitcoin.
black listed or not, those coins will find always a use for some people, they are here to stay no matter what happens to bitcoin, because they offer something that for someone is valuable a lot and that bitcoin does not serve in a successful way, privacy and anonymity
those coins can become obsolete only if sidechain will promise the same anonimity via zerocoin or darkwallet