They didn't pick Tron, they didn't pick Ethereum, they picked EOS. One of the largest DAPPs on the NEO chain is switching this April for performance reasons.
You can read more about it in their medium blog post here:
When our team first discussed the requirements for The Effect Network, it quickly became apparent that we require a blockchain that is scalable, secure, and stable. At the time we made the decision to build on the NEO blockchain, as we felt it had a huge potential to become one of the best blockchains out there. The major compelling technical reasons were: free transactions for end users, high transaction throughput, and multiple programming languages for smart contracts. However, in reality, things turned out differently and the current state of NEO is not up to speed with what we need to be able to build out our Network. NEO’s free transaction system for end users turned out not to be viable as they coped with multiple malicious spam attacks, the current state of the blockchain has a limited transaction throughput, and the smart contract compilers, besides C#, are quite immature.
As the building and development of these blockchain protocols and systems are still in their infancy and growing pains will surely continue in the years to come, we found that the technology and the direction of NEO was not going to match the ambitions of this team and project. Over the last few months our core members explored many blockchain projects that have arose over the years in order to find a more suitable alternative. We dove deep into protocols like Ethereum, Komodo, Tezos, and a handful of others. There were several advantages and disadvantages to each of these protocols, but there was one that stood out above the rest: EOS. We found that EOS encompassed the most features and scalability options, which we know are essential to build a good foundation for the future of our development efforts. Simply put: EOS is scalable, easy to iterate upon, fast, technologically advanced, secure, has high TPS, and has a great community and ecosystem.
For more information on EFFECT.AI:
Effect Force: https://force.effect.ai