If this were the only study which looked at eating in restaurants, you’d be right to take this skeptically.
However, you’re ignoring the recent, real-world studies of air circulation and its effects on SARS-Cov-2 transmission, and those have demonstrated conclusively that rates of virus particles in the air are higher inside than outside when an infectious person is or has been present, and that a restaurant ventilation system which blows air across or next to a table with an infected person towards other tables is spreading virus particles to the other tables (and increasing their infection chances), even if they’re 10 or 15 or 20 feet away, depending on the air flow. And talking, laughing, yelling, walking through the restaurant to serve or bus tables or go to the toilet, etc etc etc all create airflow that is chaotic and hard to predict - but in an enclosed space, promotes the distribution of virus particles.
Outdoor air movement has also been proven to dilute the particles in the air much more effectively than indoor air movement.
The facts - facts, not opinions - are that with current ventilation systems, it is more dangerous to eat inside a restaurant than outside a restaurant. And some restaurants are more dangerous than others - but we can’t determine which are better without a careful airflow analysis. This study is just an attempt to roughly quantify a danger we have already proven exists.
Accusing the facts of “wanting to keep restaurants closed” is silly - they’re just facts. And we either pay attention to actual facts, or we ignore them. You sound like you want to ignore them. Bon appetit, and welcome to a much sicker, more deadly October and November.