Those schools use the big full-page ads because they suck in the uninformed. Those with little or no knowledge of commercial aviation automatically assume that pilots "have go to a school" to learn to fly. They assume that large and loud equals prestigious.

Unfortunately, pilot licenses do not get you a job...flight experience gets you a job. Nobody cares where you got your licenses, because you have no experience and are not yet employable outside of flight instruction in small airplanes or very few other niche jobs.

The exception is military flight training, that will get you first crack at the best airline jobs (if you fly fixed-wing aircraft). But of course those who complete military training must fly in the military for 8-10 years so they also have plenty of experience when they apply to airlines.

For civilians, do a lot of research and find a small local school or FBO with a decent reputation. Keep your day job until you complete all your ratings (except ATP) then start flight instructing to build time. Aviation is a VERY personal business...you have to get out and talk to people face-to-face. Those who think they can start their career by browsing Flying magazine and picking out a school are delusional...and there are plenty of scam artists in aviation who will take their money.

Do your research and you will save a bunch of money and avoid near-six-figure loans which cannot easily be serviced on entry-level pilot pay.