As someone who lives in Texas, that part seems pretty clear. If a company offers a service but intentionally excludes people from Texas (or any part of Texas) because of where they live, that person can sue here for damages.
This is a pretty wild concept. So if I am a citizen of, for example, north carolina and I decide that I simply don't want to sell widgets to citizens of Texas can I be sued for breaking a Texas law? Do you have a link to somewhere that spells that out? Not that I don't believe it, I'm just not sure how that could ever be enforceable. Are they going to put texas police in a car and drive to North Carolina and arrest me? Sieze my non-existant texas assets? There is no Texas FBI with jurisdiction outside their borders. What possible penalty could I have for simply ignoring the lawsuit?
A state ban on a nationwide company could also extend to its vendors and customers, so platforms could be cut off from advertisers and suppliers here. This technique has also been used in CA and in Europe to widen the compliance net.
But surely if my goal as a company is to not interact with Texas customers due to restrictive or objectionable Texas legislation, not letting me do business in Texas is 'threatening me with a good time'?
/s