Yes, I`ve heard it is harder to make scams in NEO platform right?
Technically there is no difference between performing a scam on ethereum or on neo.
Ethereum has gained a lot of attention in the last year. This has attracted a lot of small legit companys, developer, so-called 'investors' and, of course, scammer.
The reason that most scammers choose to perform it on ethereum over neo is because ethereum offers a bigger audience (and therefore more people to steal money from).
Why would they using neo to scam people if they could make much more money on ethereum?
I am not sure, this is the only reason. As of my understanding NEO has gotten more constrains from chinese governement in Terms of planned ICOs. I guess it is not so easy to release something new on NEO Plattform without going through a thorough scan. Actually I guess a promise for Investors to deal with more legit ICOs on the NEO plattform.