Yeah, but your way with mixers and exchangers is more difficult, dangerous (i mean using mixers) and demand more time to make it. With coin like Monero you just buy it, and after that buy something what you need. (more comfortable).
But in anonime coins you must for sure know that that coin are real anonime (what we can't say about DASH, as an example)
At one point you must buy alts on that same exchange if you want to posses, or maybe you can buy it here from members with higher trust. But still everything of this is very risky. In this case best is to be a miner, and how meny time i mined crapy coins and now i cannot rid of them.