These are too extremes, which frequently result in the same outcome. What I notice is that it's not one or the other, but most times both- contributing to the disability of their child by doing too much, things the child can do themselves, usually out of guilt or a misconception that the child is not capable. And giving too little in other areas- providing things instead of their time and attention.
Somehow (pop psychology 'experts'?) have instilled the fear in parents that they'll cause their child psychological damage by saying no and setting limits. Setting limits often results in a tantrum-parents worst nightmare. They can not bare to hear their child cry, so they bribe, distract, entertain... anything to avoid their own discomfort.
The stakes just get higher as the child gets older, and at some point the child sees distraction and bribery for what they are- manipulation. The child is robbed of a valuable lesson- you can't always get what you want- no matter how loud you scream. Kids need to know this by two, and certainly by four- when the tantrums can be louder and more violent. And heaven forbid you wait until their teens. Disappointment is easier at two than 14. Not that they master it at two, but a neural pathway has is set (software installed) for future reference. Teachers and others who come in contact with the child are not going to use bribery or distraction. They will expect some level of social skills and cooperation. And the child's peers may not take to kindly to their 'entitlement' behavior either. The kid may end up getting decked and/or shunned when they act as though their wants trump other's.
I think this is why so many parents end up disliking their kids, and are clueless about what to do. They could start by saying NO when their 18 month old pulls their $200 rx glasses off their face and mangles them, instead of nervously chuckling or rolling their eyes and shrugging their shoulders- like 'what's a parent to do?'... because they fear what others will think if they set a limit and 'make' their kid cry.
The child is conditioned (programmed) to believe that s/he can do whatever they please. Any wonder they reject limits when the parent later reaches a breaking point (when their little manipulative tricks no longer work) and does what they should've done at two?