yeah agree on you, many project and people used this kind of stuff to invest a lot of investor and turn it to be a scam, but i dont think tachain will do this kind of things since many people are still speculating their project.
I've experienced these key things in the projects that I joined especially with the ICOs. Sometimes they extended their ICO because they did not reach their softcap even though they promised the date was not fulfilled and they continued extending the extend.
Continuous extension is never good for any project and even if they tend to extend, it should be a situation where its fixed and adhered to, otherwise, it will look like a ridicule to everyone involved, so its of essence that stipulated dates be maintained in order to create confidence in the community, where there is confidence, there is productivity
You are very correct, the problem is not extending but continuos extension with no proper date and all. Such project is not a serious one and are only in for the cash and will probably give up in the long run.