I would be very opposed to keeping cars off the grid. For many years now, we were wishing and hoping for larger grids, some silly season years desperately scraping up cars, hoping to make 20, worrying about the declining field.
So now, if we are in a position to have a field of 27-30+ cars, they all managed to put their sponsors in order and make the race, and within 107% (or whatever percentage is deemed appropriate), then by all means, let them race. If you shut out some cars, eventually they run the risk of losing their sponsorship, and disappearing altogether - the last thing we want, right?