It's a valid philosophy when acquiring a high mileage car that appears neglected or has observable oil issues. The OP states that he observes new oil turn dirty instantly. This would be a good case for doing some short OCIs to attempt to rehabilitate the internals. Oil is really cheap. A Lexus and it's engine are very valuable. This is a no-brainer. It's not going to harm anything by doing some short OCIs, and it is almost surely going to improve this car, or ANY car could benefit from such things. Again, when you do an oil change, there's ~10% you cannot get out, and that 10% might have contaminants, really old oil, sludge, water, who knows. So even in a healthy engine, another quick OCI will in fact get nearly all of that last 10% out.
Spending $100 on oil is better than losing the $5000-$10000 value of a Lexus.