People who actually need anonymity need to hide among traffic that is boring. If you reduce the number of hops your crawler is using, you're reducing the amount of boring traffic and making it easier to find the interesting people.
Running a relay in addition to using Tor in the normal way is a good idea, however, as it increases the bandwidth of the network.
In fact it is a bit more severe than that as you are effectively deanonymizing yourself. If everyone else is using a 3-hop circuit but your crawler is using just 2 hops, it wouldn't take much effort to isolate your activity in the network since you're effectively standing out.
But if the received wisdom becomes "if you're not rebelling against an oppressive regime, you should only be using 1 hop" then the advice has real harmful effects.
People who actually need anonymity need to hide among traffic that is boring. If you reduce the number of hops your crawler is using, you're reducing the amount of boring traffic and making it easier to find the interesting people.
Running a relay in addition to using Tor in the normal way is a good idea, however, as it increases the bandwidth of the network.