With the high difficulty and low value of BTC, I would warn people against any kind of BTC mining, not just cloud mining.
You're talking about two very different things here, I feel. Telling people they should only contribute to securing the network when it's profitable sort of defeats the long-term objective for miners, which is profitability. If you think about it, the more secure the network, the more unlikely it is that anyone can ever attack it successfully, the more valuable the network becomes, the better this reflects in BTC price.
Cloud mining is a sham at worst, misleading at best. But mining itself is quite another beast on its own, and not everyone does it with the same immediate need for income gratification.