There are both pros and cons with this. Stealth camping as a way to sleep in a crowded area where there is no other way to go (I'll use SXSW here in Austin again... any CG in a 50 mile radius will be full, and charging $100 a night) might be doable. Wallydocking? Doable, but again, use your danger sense.
There are times when stealthing is good. For example, if taking I-10 and one is getting dead tired west of Van Horn or Fort Stockton, finding a good (secure) hotel, paying for a room and getting permission to crash for a night may be safer than some CGs near El Paso with the reviews being, "keep your .45 handy." In fact, some hotels/motels may offer electric or other services. It is more expensive than a CG spot, but if you don't feel at ease, you are not going to get any sleep anyway.
Another time is when in a small town and there isn't a CG anywhere in the region. A van parked at a church or in front of a business is going to attract a lot less attention than one parked on a residential street with a "free candy" sign on it.
Stealth camping as a way of daily living? Not in today's America. Every so often, these RV forums get a college student who thinks he can save on rent or dorm fees by buying a beater van and crashing in a parking lot. After he finds out that parking in a constant location is impossible, finding showers is tough, and constantly having to deal with the law (since people will call the police on a van if they hear any noise, see the van move, see a wisp of smoke from a vent, or just because it is just a van), this idea tends to get extinguished.